. Smoke which is basically the visible products of cumbustion is due to poor combustion.
Can you check yourself whether Air filter is clean ? ,It might have leaves , Debris etc , Check Oil Level . Also fill from different fuel pump as sometimes it is more adulterated at some pumps . HP is the best one in Delhi any one you visit .
My advice is to visit your nearby mechanic and let his test the car for the problems as it save you money . If you go ask him to check valve stem seal and rings checked .