Visa for 6 months

Dear Sir/Madam,

I am sri Lankan citizen who employ of Canada based apparel buying agent, Pls let me know how can I get visa for continues 6 months staying at Shanghai and Ningbo . Since need to visit our suppliers & stay there for 6 month for inspection.
If yes what documents are required?
And the same time can I apply via your Egypt embassy, since now I am staying at Egypt, if yes what are they require documents to submit.
Regards,
V. Nilendra,