You can work from the attached circuit. It should give you a good starting point. That is about it as nobody here will do the complete school project for you. Look at the circuit and understand how it works.
The reason why IR is used is because the hardware is not very bulky, but to increase the range a radio wave based system may be used (I am guessing here), but with a longer range the hardware size and power requirement would also increase.
Instead you could modify your requirement and make system that calls your cell phone when the car door is opened. I suppose this should not be difficult, and the power for the transmitter could be derived from the car's battery.
But thing is i just want a tracking system so that i could locate my bike(not car)from many using some lights and buzzer. I don't want any burglar alarm system
in short I want a long range remote operated lights and buzzer.
Right now you have this same line of questions running along in two threads. This thread by title has nothing to do with your objective. I would suggest you keep everything in this other thread as it will lead to you getting better help and advice. In the other thread I provided a few links. I am not trying to discourage a home brew method but designing and building boards for RF applications is not quite an easy task.