Hi Dipesh you should make it clear about which exam you are refrerring to if we talk about NEET then you need to have a minimum of 50% aggregate in the Science stream (Physics, Chemistry, Biology/Biotechnology) if you belong to the unreserved category and 40% if you belong to the reserved categories.If we talk about JEE then you should have 75% marks in aggregrate for general category.For any other courses like BA or BCOM you need atleast 50% marks.My advise would be to  you should give the Improvement exam if you wish to. It is better if you do. It will help in avoiding problems at the time of submitting applications and giving entrance exams.

Hope it helps.

Hello Dipesh :)

Since I don't know which field you are asking about, I'll tell you about the medical field.

To be eligible for NEET, you need to have a minimum of 50% aggregate in the Science stream (Physics, Chemistry, Biology/Biotechnology) if you belong to the unreserved category and 40% if you belong to the reserved categories.

Since you have scored 49%, you could give the Improvement exam if you wish to. It is better if you do. It will help in avoiding problems at the time of submitting applications and giving entrance exams.
Most exams require a minimum % in 10+2.

All the best!
Hope this helps.

In the 12th class if you have got the less marks then you might not be eligible for National level exams like BITSAT JEE mains and many others but there are not closed door for you.
Many colleges in India still takes the students with having less marks in the 12th class so you can apply in those collages otherwise if you want to improve your marks in 12th then you can fill the form for the improvement also