I need ur advice, Must i be a 1st class, 2.1, 2.2 or can a third class work?

hi all. sorry,i dissapointed you! really,i am not cleared about sometin and i need u to advise me.i have just been posted to Oyo 4 ma service and i need to know the parameters they use in posting people to places of primary assignment.Must i be a 1st class, 2.1, 2.2 or can a third class work in a bank? how is dat possible? Can a 2.2 work in a bank like zenith,phb etc?has it happenned b4? I also need to know what exactly i need to buy b4 i leave 4 camp.can't wait to have ur replies.thnks all