You should report to the loss of the passport as soon as possible to the nearest police station and get an official police report regarding loss of passport, then go to the Indian embassy or consulate in China to apply for new India passport:
Following documents/papers are required:
• Police report regarding loss of passport.
• Photocopy of the lost passport, if available. If not, particulars may be provided.
• Applicant should submit a written application stating the circumstances under which the passport was lost.
• Four recent passport size colored photographs along with duly filled in application form No: EAP-I.
• Fee: RMB 1035.00.
Note : Duplicate passport is issued only on receipt of confirmation from the concerned Regional Passport Office in India.