Hello  aspirant

hope you are doing well and safe. With reference to your query,  I would glad inform you that in top btech colleges of india like NITS,IITs admission are done through the rank scored in JEE-mains. Even state universities have now starting accepting jee mains for admission . Though you have scored a great percentage in 12th but still you have to be appear in entrance exams for admission in government college for btech but you can look for private universities like Amity ,galgotia for admission

Hope you found this answer informative. Best wishes for your future