work visa -Z REQUIREMENTS

Iam located in Bengaluru working for government of India undertaking. Understand that to get invitation letter for work Z type, photocopies of passport/resume/assignment letter are to be duly attested by notary public,chamber of commerce,ministry of external affairs & finally Chinese embassy in India . Which embassy in India I should approach ? Can I do it in New Delhi as my head office is located there? My passport is isuued in Bengaluru.