If there are mistakes in your personal particulars in passport, you can submit that passport at the Passport Office for correction at the Correction Counter.
If the mistakes were made by you in the original application form, then you should apply for the correction in category 'R' by submitting form no. 1 (The Application form which you had used for getting new passport, now for a re-issue of passport ) and a fee of Rs.1000/ would be charged.
Online registration is not required in this case.
Fill the form (Form No.1) and with the required enclosures n fee, approach the passport office (Regional Passport office, Kummaraguda, Secunderabad) in person and submit the same at the Correction counter.
Please refer to the link below for all your passport related queries and application requirements for specific purposes.