For the caste change in your document ,you have to fill up a "gazette application form for change of name in birth certificate and school leaving certificate". You can download this form easily and can complete the process online only. There are two types of gazettes:-
1. General Gazette - It can be done in 60 days and the rate is Rs. 550 only.
2. Tatkal Gazette - It can be done in 25 to 30 days and the rate is Rs. 1100 only.
The documents required for Name change In gazette for Major / Minor :-
For Major / Adults ( Mandatory Documents )
ID Proof : Pan card or Passport or Driving Licence or Aadhar Card or Voters Id
Address proof : Ration Card or Aadhar Card or Electricity Bill
Photo : One Passport Size Photo
Application Form : Duly Signed Application Form with all details Old & New Name, Correspondence address, Contact Details & reason for Name change
For Minor below 18 years (Mandatory Documents)
ID Proof: Aadhar card or School id or Aadhar Card
Address Proof: Ration card or Aadhar Card
Age Proof: Birth Certificate or Bonafide
Photo: One Passport Size Photo
Application Form : Duly Signed By Minor if possible and parents or Guardians
As its a Online process all the documents need to be in JPEG format with File size