Alright, so I'll assume these things

• that you wish to go with the merit seat and not the payment seat.
• You come under the general quota.
• You didn't do your 12th from these states : Kerala, Tamil Nadu, Karnataka
• You are not from Andhra Pradesh
• This is with regard to BTech admissions

Merit based :

Now, the counseling is done in some 3 phases. For the first call, they'll call the ranks from 1 to some 4500 for general quota students (I.e students who don't belong to SC, ST or State quota) . They'll simultaneously keep updating the seats being filled up across the campuses on their official website.

If seats are still available after the first counseling, they'll call the next set of ranks, 4500 to some 8500. By this time, mind you, almost all seats from well to do branches in the Coimbatore campus would already be filled up. So your only chance are the Bangalore and Amritapuri campus. I got a rank of 7000 so I got a call in the second round and got admitted to the Bangalore campus under CSE. But by the time my name was called I think only 24–25 seats were left in the Blr campus.

If seats are still remaining after the 2nd counseling they'll call the ranks till about 12000 but getting a seat is fairly by luck in this case,ie, only if there are seats still left till your rank is called.