Hello Ankit,

Firstly congratulations on your GATE score. candidates must remember that each institute whether an IIT or an NIT will determine their own GATE cutoff for IN. Varied factors are taken into account by different institutes while they determine the GATE IN cutoff. Each institute has different  GATE cutoff for instrumentation engineering for different categories.

The parameters which are taken into account while determining the GATE cutoff 2019 for IN are given below:

• Number of candidates appeared for GATE 2019
• The difficulty level of the exam
• The cutoff of GATE for previous years
• Availability of seats

https://engineering.careers360.com/articles/gate-cutoff-for-iits

Check the above link to know about the previous year's trends in VArious IIT's.