Ravish, as your provided with an accommodation and transport you do not need to carry too much money with you.
2000 - 4000 would be good for a mediocre lifestyle. otherwise if you plan on clubbing every weekend and eating at some of the most expensive places 4000 would not suffice. when i came down first i was living on QR 500 for the fist month.
it all depends on the lifestyle that you want to maintain during your first month.