Hello Vishal,
You should score a minimum of 75% for getting admission in good Engineering colleges.
Best of Luck !!!

Hello Aspirant,
If you want to be on a safer side there is nothing such as minimum marks. The greater you score the more safer you are because when the entrance scores are tied the next criteria which comes is your marks in the previous criteria. So the more you score, the better it is.
Thank you

Hello dear, for better future you should have to  give your best in the exams. If you want admission in good colleges you should have to score Atleast 75%  in Higher secondary examination conducted by respective boards(class 12). If you cross the criteria then you can eligible for doing btech in prestigous institution of India. 

Hope this helps you. 

Good luck.