The cut offs for different NITs,IIITs aren't out yet by the councel members so you need to wait till the results are out till then you may check your rank from the jee main rank predictor of Career360 and can also check the last yers opening and closing rank of government colleges for your category though 78 marks aren't that good to be able to get some good government college but as you mentioned you're from the obc-ncl category so this may proved to be a helping hand for you but still I am afraid you won't get top branches like CSE and IT as their cut offs are usually high than the rest. I am providing you the links for both the rank predictor and the previous year's opening and closing rank of government colleges linked with jee main they might help you to get an estimation.

https://engineering.careers360.com/jee-main-rank-predictor

https://engineering.careers360.com/articles/jee-main-cutoff-for-top-nits

Hope It Helps!!