If you have your Indian driving license, you can appear for direct test without lessons. It will cost you 50+200. You will have 2 chances in total to clear the test.
For school, I am attending Al Rayah Driving school in Madina Khalifah. They are charging 1950Riyal for 12 days course.

I appeared for direct test, but failed the parking and then got enrolled in school. You better get this short course first and then appear for test. Parking is a bit tricky and one must know the rules to follow on the roads in Qatar. For this, 12 days classes are enough.