Mechanical Engineering

As you done B.Tech in mechanical engineering then go for M.Tech in mechanical engineering, it is a better option for you. You can do M.Tech from any private college, but as per me, you should prepare for GATE exam.

The cut off rank and marks vary each year as it depends on the number of applicants and the difficulty of the question paper. Your AIR shall be below 4500 to get a seat for mechanical engineering in IIT BHU, Varanasi.

For your first question, my answer would be that you check the official PCCOE website.
www.pccoepune.com
You can get admission into the college by 3 ways:
1) According you MH-CET marks. (By checking cutoff trends for respective branches)
2) According to your JEE rank and marks (by checking cutoff)
3) Institutional level seats (seats remaining after all CAP rounds are conducted). You may or may not get your desired branch.
4) Management quota (for quota fees consult the college directly)

Hi Aniket,
You are suitable only to study in India. Your grades are very poor and also you should know that the practice of donation system exists only here.