That all depends on how complex the transacations are and how well indexed the tables are.
If the tables aren’t indexed correctly and the transactions are complex then a couple of hundred per second may be to many.
If the tables are well indexed and the transactions are small and simply then thousands could be fine.
It also depends on how much data the database has that the transactions need to access.
In other words I don’t think there is enough information to give you a solid answer.