How do I get visa for hk and how many days for processing and what is needed to apply?

Nimesh, first, prepare those documents: copy of passport, the application form, a bareheaded color photo, financial support proof, transportation and accommodation arrangement, residence permit in Guangzhou, and your travel itinerary.
Next, post the application to HK immigration department. Below is the postal address:
Receipt and Despatch Sub-unit
HK Immigration Department
2/F, Immigration Tower
7 Gloucester Road
Wan Chai, HK