Both PGDIE and PGDIM are very good courses for a mechanical engineer, but the syllabus for both these courses is different. 

PGDIE

1. It is a flagship course of NITIE which is more focused on industrial engineering. To get admission to this course, you have to clear the GATE exam.
2. As a fresher, you can make up with most of the students in your branch but you might not be able to contribute as much as the students who have significant experience, especially in class discussions and group activities. 
3. But there won't be many problems during placements as there are many companies who are looking for fresh candidates to join their team, especially in the FMCG sector. 

PGDIM

1. It is a management course that is equivalent to an MBA course, and to get admission in this course, you have to clear the CAT exam.
2. As a fresher, if you take admission in this course, you would probably be in the minority as most of the students would have some kind of work experience. 
3. There will be certain projects which would need some kind of experience and here your other batch mates can be a step ahead of you. 
4. You will have to do a lot of reading and communicating with all your batch mates, professors to learn how a business works. 

Both the courses are very different from each other and now it depends on you in which field you are interested in. If you want to pursue a management course then go for PGDIM or if you want to be in the field of engineering, then you can choose PGDIE. 

If you are asking from a technical point of view, you will not face any issues for doing PGDIM from NITIE once you have completed your M.Tech.

But, in the future, you might be asked during an interview as to why you have pursued a management degree after completing your master’s in a core field. Be prepared to give a convincing answer. 

If you are thinking of joining the industry and then doing a management degree makes sense. It would definitely help you scale up your current job prospects. But, if you are pursuing this degree without any industry experience, it might come off as a little haphazard, like you are jumping from one degree to another. This might confuse your recruiter a little if your final goal is to bag placement in a decent company. 

You can go ahead but think of a good reason as to why you want to pursue this to ensure that you get placed in your future and don’t face any problems.

The minimum percentile to get admission in PGDISEM depends upon the number of applications received. In 2021, the cut-off for General was around 86, for OBC it was around 75 and for SC/ST it was 65. 

The batch size is very small which is an advantage here. Only 44 seats are available for this program. The placement drives are quiet and relaxed compared to other branches and there are chances for every student to get shortlisted. Some companies hire students only from PGDISEM courses for certain roles such as EHS and sustainability and the average package offered is very good compared to other branches.

The percentile required to get admission in this course is definitely on the higher side, but the amount of facilities and freedom you get while pursuing this course is a big advantage over other courses. 

NICMAR does not give 100% placement. You can confirm this from any of the graduates from the institute.

• At NICMAR, for a PG in the quantum survey program at Hyderabad, you will get a package of 4 lakhs minimum. For ACM and other two years program packages, it will reach around 4.5 to 6.5 lakhs per annum.
• Various companies like Asian paints, Hilti pay around 12 to 14 lakhs per annum along with Skoda but it is only for business development profile. As per the information above, you can get a minimum package of 4 lakhs if you are a fresher with an average academic record.
• Therefore, if you have not taken out a large loan and you feel that with a bit of savings and a package of 4 lakh you will be able to pay off the loan, then go for it. But if you belong to a middle-class family and plan to take a loan of 14 to 16 lakhs then this will not be a wise move for you.
• The situation of the industry is not good at all. L&T, Shapoorji Pallonji, and some other companies are the only ones that pay the salary on time. Various companies like simplex, HCC have a 1 to 3-month delay in paying salaries to their employees. A lot of graduates tend to start from site execution as Assistant project managers but the work pressure is too much for them and they give up after 1 to 1.5 years.
• From the current CTC, the hike is not that much and somewhere around 12 to 15%. There are various engineers from NICMAR with 10 to 12 years of experience who are still working with an 80,000 salary in a construction company as AGM/ GM. A lot of graduates also join corporate interior companies with a package that is even lower than the construction company.

So, it won’t be wise to opt for a two-year ACM or any other program if you belong to a middle-class family and plan on taking a loan. You can rather go for a PGP quantity survey which is for one year or you can study hard for CAT and opt for MBA from a level 1 B-school where you will be paid well and will have strong career growth.

I think I can give you an idea about the opportunities that you will receive at NITIE since a have a few friends who graduated from the institute. 

• NITIE Mumbai is a premier b-school under the Ministry of HRD in India. It is famously known as the “Mecca of Operations and Supply Chain Management” in India.
• The alumni base of NITIE is 50+ years old. They work as the lead in many companies across the globe.
• NITIE is located in the financial capital of the country, with many company headquarters within a radius of 10-15 km. Which is beneficial in terms of placements and exposure.
• The faculty members of the operation and supply chain management are of top-notch.
• You will get ample opportunities to take part in various case studies in the area of operations from the first month of the first year itself. In addition to this, you get an opportunity to work on weekend projects under many start-ups.
• Maha Mandi, which is a Socio-Marketing field event, is organized by NITIE every year to provide an experience of Sell in the streets of Mumbai to its students.

These are a few of the opportunities that you will get at NITIE. 

My brother is a mechanical engineer who took the path you're planning to take. You can surely do ACM from NICMAR. Although, I will recommend that you do it from the Pune Campus. 

It is better in terms of Placement opportunities available. It is more diverse and will help you in being exposed to varied perspectives.

A lot of opportunities await you as a Mechanical Engineer in the Middle East in HVAC and in the MEP Departments of Construction Companies.