what is process for visa and where to apply from chennai

Kumar, then I think you need to apply from HK Immigration Department directly by post. It takes four to six weeks to deal with your application. The required documents:
1. finished ID922A form
2. a recent passport photo
3. copy of your passport information page
4. proofs of your diploma and working experience

Your sponsoring company should provide:
1. completed ID922B form
2. copy of training contract with the trainee
3. copy of business registration certificate
4. Photocopy of proof of financial standing, profit tax return, for example
5. company background documents
6. Detailed business plan