Name Correction in ALL Certificates !!!! Urgent help needed

Dear all, my name is Syed Khaja. My�SSC, Intermediate, Degree (Osmania University) and �PG (Osmania University) marksheets having the name as Syed Khaza and all other�degree certificates... The spelling mistake started from SSC in the year 1996. 1) I want to change my name�Syed Khaza TO�Syed Khaja in all my certificates. 2) In my passport, it's by mistake Khaza Syed. I want to correct passport too with Syed Khaja. Note: I don't have Aadhar card yet. I am 1979 born. Can you tell me the procedure. if yes how to change it ? what should i do? How much time it will take approximately?? I am from Hyderabad. Please let me know in detail. Thanks a ton in advance !!!