Mr.Rajesh, I think you can get the visa on the same day of application. The fee for multiple-entry visa with half year validity is 400 HK dolalrs. The fee for multiple-entry visa with validity of one, two or three years is 600 HK dolalrs. The fee for 1 working day processing service is 250 HK dollars.
Requirments for F visa
1. Valid passport (at least nine months before expiration) with blank visa pages. Because you want to Multiple Entry, so your passport at least have 9 months remaining validity
2. Completed Chinese visa application form, one colored passport photo taken in the last six months
3. Visa Notification Form, or an letter issued by the company he/she is employed and the registration license of this company, or an invitation letter from the mainland company ant the registration license of this company.
4. Under some circumstances, the applicants may be required to provide financial proof, a copy of Chinese hotel booking and return flight ticket booking.