kanika...OBC candidates also need to have 75% marks in 12th for being eligible for admission in IITs,NITs,IIITs and GFTIs...but don't get disheartened as there are many other colleges in which you can secure admission through JEE mains even if you don't have have 75%.
But sadly you cannot appear for JEE advance.
You have also mentioned that you are interested in VIT, but this year VIT is offering admission based on 12th board marks and JEE main January session score.If you have appear for it and scored well then you can get admission into VIT.

Aditi amrendra Okay thank you mam but mam I have to do it JEE mains is crack for good marks so,then I give to the best collage mam yes or no mam please mam answer me and thank you so much mam thank you so much

Hello maam my overall percentage is 66.2 and 20 marks in physics thoery which is near to passing marks. Is there any chance of gracing marks . If yes then kindly suggest me what should i do?

preeti kumari dear preeti..results are already declared so there is no way you can get grace marks.
But don't worry...you still have chance to perform well in JEE, try getting good percentile in JEE and there are many other good colleges too where you can get admission