Hi I want to setup up an exchange company (remitance of money).the money comes in and goes its clients money I only make profit from exchange rates . What company is best to open in usa any state taxes I need to pay or any other taxes please help me

Where is this at ? If US, yes you will have to pay state and federal taxes.

Depending on the exact services, there may be additional federal permits and rules.

What is being exchanged ?

So you want to act as a remittance agent, you will be liable for tax on the fees you change