You should apply for work visa to China in person, your employer can give the below 2 documents to you for Z visa application: Alien Employment Approval and Visa Notification issued by an authorized unit in China (original)

You also need to prepare other requirement for work visa application, such as:
(i) Original passport which has more than six months left before it expires from the date of application and sufficient blank visa pages.

(ii) One completed Visa Application Form (e-Form / Download) with a recently-taken passport photo stuck on it;

iii)Covering letter from applicant.



(iv) "Physical Examination Record for Foreigner" issued by doctors from an Indian state hospital. The photo on the Record should be stamped by the hospital.(Valid for 6 months from issued date)

(v) Photocopy of the personal data page of applicant's passport.

(vi) Photocopy of Applicants Educational qualification or Professional qualification