Can I take a drop for UGEE?

Yes, you can, but only if you passed Class 12 not so long back, i.e., this year or last year, your subjects in Class 12 were Mathematics, Physics, and Chemistry and you scored minimum 60% aggregate in PCM (minimum 55% in case of SC/ST students)

Not eligible if you passed Class 12 more than a year ago.

Basically, single drop year is allowed for UGEE. You will not be eligible under this admission mode if more than that has passed since you passed Class 12.