Among the given options, SIT Tumkur is definitely a better option. It offers better placement and exposure as compared to RNSIT and KLE.
KLE isn't ideal when it comes to its location, therefore, I would advise you to not choose it. Since it is located far away from the main city within Bangalore, it gets pretty inconvenient for the companies to show up for placements. This gravely affects the placement scenario. You would as well be devoid of opportunities like off-campus placements, startups, or even as mentioned, transportation.
If you are a North Indian, never choose a college that is located at a far-away destination from Bangalore because of how inconvenient things would get because of the transportation factor.
However, if we talk about SIT Tumkur, the location of that institute is ideal since Bangalore is not that far from it. It is around 80 km away, which boosts the placement stats along with the ranking of that particular institute.
RNSIT is in Bangalore but it is not as good as SIT Tumkur.
SIT Tumkur is a decent choice. Both the ISC and CS branch faculties are very well established as compared to the other faculties in the college. The syllabus is also very well updated and is set according to industry standards.
A number of different companies hire students from a number of different branches with decent packages of INR 3 to 7 LPA. Many different companies like TCS, Accenture, Siemens, Bosch, Byjus, etc. visit the college annually.
Lastly, if you want a fair comparison, my advice to you would be to visit both colleges and get in touch with the departments, their students and seniors. You are basically going to invest 4 years of your life here.