For example, some people have offered me price, and I am waiting for last person
so I tell him
Can you offer your price quickly? Because I have some offers on hold, that I have to reply to those people.
You can say "on hold" here, yes.
You can also use "at hand" or any other expression that conveys you have offers lying around that are pending.
Side note: I'd suggest
s/that I have to reply to [...]/and I have to reply to [...]/.