Amit, Please tell me some more about this issue.
Is the oil level low or is the display inside the car telling you to add oil. There is a bulletin from BMW regarding this issue. It might require replacement of the oil level sender and recoding the lamp control module.
Also, BMW has recently stated that oil consumption issues have been reevaluated and 1.5 quarts in 1000 miles is nominal for some of their products.
Please repost and stay in touch