Which incoterm is mostly used in freight forwarding operations?why?

I believe C&F or CIF.

Although answering this question is tough to answer as ex works and fob are also used especially in partial load goods.

C&F is most commonly use Incoterm but now FOB is also flourishing due to extra destination charges

CIF C&F and FOB, DDP also used...

Depend upon the order or goods to be purchased or shipped.Mostly CIF is being considered if the supplier is more professional 

(1)Ex-work (2) FOB (3) C&F (4) CIF-- 

http://ar.wikipedia.org/wiki/%D9%85%D8%B5%D8%B7%D9%84%D8%AD%D8%A7%D8%AA_%D8%AA%D8%AC%D8%A7%D8%B1%D9%8A%D8%A9_%D8%AF%D9%88%D9%84%D9%8A%D8%A9