Hello Pravin,

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 Mechanical. Varied factors are taken into account by different institutes while they determine the GATE Mechanical cutoff. Each institute has different  GATE cutoff for mechanical engineering for different categories.

The parameters which are taken into account while determining the GATE cutoff 2019 for Mech 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.

For PSU's it depends on the rank that you have been obtained. If your rank is below 500 then u might have higher chances to get into PSU's.