If you want to became a scientist then only neet is not the option their are several exams in the field to become a scientist .

Like if you want to become a scientist in agruagricul field then you have to clear ICAR exam , if you want to become a scientist in space research field then you can go through the exams held by ISRO , if you want to become a scientist in the field of human biology  the .You have to clear the neet UG then neet pg and then phD in medical field. 

Know refer the field in which you wanted to become a scientist then give the exams