visa to HK

Bishal, you can find the relevant application form at the website of HK immigration department and you can find relevant information at the website of PRC embassy in your home country.
You can apply for a visit entry permit which allows you to attend the conference in HK. First, you need to prepare the relevant required materials including your passport and its copy, the application form, a passport-style color photo, your travel plan, flight itinerary and financial support proof. Afterwards, you should post your application to HK immigration department directly.