It depends on the context,your sentence can be 2nd conditional which is an unreal present or future condition so it'd be 'If you worked,we would talk later'(although it sounds a bit awkward to me it can be 'if you completed your work,we would talk later') and as you have used 'had' in if clause so it can be 3rd conditional then it'd be 'If you had worked(completed your work),we would have talked later....remember 3rd conditional is used where we talk about thing(s) that didn't happen and it claims....

Depending on what you're trying to say, "if you have to work, we can talk later" or "if you're working, we can talk later" can be used. The first is used when you're talking to someone now, and they are currently (or will soon be) working. It implies that 'not working' isn't an option. The second is used if you are speaking to someone that is currently working.

It depends on context. But If I understand what you are trying to say sentence would be: If you would have work we could talk later (general speaking of possible situation) If you have work we can talk later (speaking of exact situation)

Thanks,Rot

SORRY "Please correct these sentences." just a typographical error.