Hi aspirant

Almost all of the PSUs have closed the application for the recruitment through GATE.Hope you have applied for them.A few like  RITES,CEL are open .

You don't have such a score that PSUs will directly call you.You need to apply for them on their official website under "careers" section.

You have less chances for PSUs as all the PSUs cut off for a SC candidate lies around 600-700 gate score.

Visit the link given to check the cut off of PSUs recruiting through GATE:https://engineering.careers360.com/articles/what-are-gate-scores-for-psu-recruitment

know more about your chances of getting a PSUs using GATE predictor :https://engineering.careers360.com/gate-college-predictor

Hope this helps you.