if i have appointment letter from china office then what are the formalities of z visa for china

You need to submit all the requirements to China embassy in India to get a Z visa. The requirements also include:
1. Original passport
2. One completed Visa Application Form (Form V2011A)
3. Covering letter from applicant.
4. Physical Examination Record
5. Photocopy of the personal data page of passport.
6. Photocopy of your Educational qualification or Professional qualification