I have aldready registered TNPSC OTR. Should I register it again before applying for all the exams?

I have aldready registered TNPSC OTR. Should I register it again before applying for all the exams?

No, it is not like that. It is a one time registration which is valid for 5 years. Once registered , you need not register it again until 5 years of completion.

You just have to enter your credentials to the application of recruitment and pay the required exam amount fees.