Dear aspirant,

Minimum marks for selection in psu iocl depends on many factors 

1)seats vacancy

2)paper difficulty level

3) Branch

So minimum marks varies from year to year 

And they evaluate you on basis of score of 100

In which 85% weightage is given to your gate score, 5% to gd and 10% to your interview and now the final scorecard is prepared.

Minimum marks for receiving any psu call is very branch specific thing and also depends on vacancy in that particular year