Hello piyush

Well,I think you know that the criteria for jee mains is 75% in boards.So,if you are not able to fulfil that,Your jee score won't be considered anywhere.So its of  no use,but yeah,if you score above 75% mains,then there is no problem because none of the top NITs see the board marks until and unless it's more than 75%.But score above 75% otherwise you can't take admission in any of government or private college based on mains score.Hope this helps.

Good Luck!