Hi aspirant,

It would have been better if you had mentioned the name of examination you want to register for but however it is very minor problem and generally it should not cause any problem while filling the form. You can register for the examination using the same marksheet and later you can apply for correction in it at the regional education office so that by the time of counselling you have the certificate in hand. In case you are not able to produce the correct certificate by the time of counselling also you can carry a self attested affidavit claiming that both the persons are the same and  the entrance is caused due to misconception and is not intentional.

Hope it helps!