Mr.Praveen,

1) Above salary is enough to "SURVIVE". You can't save much.
2) one bed room accomodation can find with 3000 to 4000, ofcourse part of villa.
3) Don't think about hiring taxi. Buy a brand new car, like nissan or toyota. monthly EMI will be 1200 to 1500.
4) no need of any stamping.
5)enquire abt the company.

Finaly, qatar is a good country where you can live peacefuly. as a beginer 12000/- is ok...

Be sure about the medical.

Good luck...