Hi last two flights when tuned to a controller i can hear him he can here me but i can only hear some of the other pilot responses not all of them so don’t know if its ok to contact the controller as another pilot might be talking
This is normal. VATSIM simulates VHF propagation. If you’re not in range of another station, you simply will not hear them. This happens very frequently in the real world as well. Use your inferences to determine if someone is likely speaking (such as if a controller just issued an instruction that requires a readback) and if so, estimate some time to give the other party a chance to respond. Ultimately you’ll likely step on someone at some point in time even though its unintentional. If that happens, ATC will work through and ask for a certain callsign to respond and then return to the other traffic.
Cheers for that