If you scored 51% in senior secondary school then yes,you are eligible to apply in ca courscourse. 

But if u scored 51% in graduation then not. Atleast 55%is required in ug courses of commerce to apply for ca entrance exam.

1.Any student who has passed 10thclass or any course equivalent to that can apply forthe Common Proficiency Course (CPC) first.

2.Post qualifying for the 10+2 exam, a student has to then qualify in CPT exam.

3.After the CPT IPCC, successfularticle-ship or training under an officially practicing C.A has to be done for 3 years.

4.Then comes the CA Final.