we want to implement vehicle tracking system, by using the attached circuit. Can you please suggest is the circuit is correct with that specifications.
Assuming that's not the complete circuit?, then the main problem is the redundant MAX232 - the GPS and GSM modules almost certainly won't be RS232 +12/-12.
You 'may' require some level shifting though, depending on their requirements - you also don't show any power supply for the two modules, nor their switching arrangements.
These days better vehicle trackers plug into the vehicles obd diagnostic port and communicate to the vehcile, then not only speed & position data can be reported, engine rpm, fuel level, any faults with the vehicle and a load of other stuff can be sent to, and it would only take a minute to plug in.