Jaggu, Christine has rightly said that red and white patches could be several things and you need to quit smoking.

How long you had this white and red patches? If it is very recent, try abstaining from smoking and eating spicy food - it should probably go away in two weeks. If it has been some time, then you should see an ENT, who may advice antibiotics first to rule out other possibilities including oral hygiene.

Do not worry too much and you'll find it difficult to quit smoking.