Hi, I play benko gambit and after 2.Nf3 (white probably wants to play colle or sth) I answer 2 ... c5 , coz i am afraid that white can still play 3.c4 and I dont wanna learn other defences to d4 like nimzoindian.

My question is: can white take the advantage of my move order? What transpositions are possible?

The Shredder online database lists 9 moves used by White, most common are d5, e3, c3, c4, g3, & dc in order. I'd say with e3/c3 white is keeping to his original plan of a colle/QP game (never heard of sth), g3 might be an attempt to go into a Catalan, d5 and dc you should already know how to handle.

but after d5 i play b5 and white is not obliged to play c4:) and by something i ment another system with 2.nf3 like london, anyway after what u have written i see white cannot punish this move order so thx for your help

After 3. d5 e6 4. c4 b5 and you have enter a variation on the Benko gambit declined, though it actually falls under a Queen's pawn game under the ECO guidelines.  On 4. dxe6 fxe6 and Black has a nice game.

This is akin to the Old Benoni defense (1.d4 c5) with the added Nf3/Nf6.  I recall reading once upon a time that it's advantageous to white to omit c4, because that square can be an excellent outpost for a knight.  If you're playing b5 as well, then it's handy for him to be able to attack that directly with the bishop.  Whether that's good or not I leave up to you, just some thoughts.

You can't avoid the London, as the correct move order for white is now known to be 1. d4 Nf6 2. Bf4.  On 2...c5, white just replies with 3. e3 and moves like 3...Qb6 are met with Nc3 ideas.

I know i can't avoid openings such as London or Colle:), my only concern is to avoid transpositions to non benko defences after white plays c4. I would like to be aware of rare systems when white omits c4 for example this one, but anyway it seems c5 after other moves is as sound as after c4