do some PSUs allow candidates with 70%in BTech but not 60%in 12th? can I still get the job at any PSU?
It depends on different PSUs. But most of the PSUs consider your graduation percentage and GATE score and this is their minimum criteria. If you score well in Gate and Interview Round, there will be higher chance of getting selected. Mainly they ask for at least 60% in B.Tech but a consistency in 10 and 12 result is also needed.