Hey kopal! 

There is less competition in the gate bt paper.

 A total of 18000 students appeared for gate biotechnology every year. If you get a rank in the top 1500's you may find a seat in the iits. 

The candidates can check the following table to analyze how much minimum marks they have to secure to qualify for gate exam.

BT 2016 - general : 26.08 obc : 23.47 sc/st : 17.39

BT 2015 - general : 26.08 obc : 23.47 sc/st : 17.39

BT 2014 - general : 25.84 obc : 23.26 sc/st : 17.23

BT 2013 - general : 38.77 obc : 37.89 sc/st : 25.85

The expected gate qualification marks for iit's 

General - 34.89

Obc - 35.61

Sc/st - 32.34

Wish you all the best!