This white patch you should not have this in your mouth.

This is not to be seen in your mouth it is called Leukoplakia.Is a reaction to an irritant, like rough teeth, badly fitting dentures, smoking, and smokeless tobacco. It can show up as white patches or plaques in the mouth, is usually painless, and can't be scraped off. Leukoplakia can also be a precancerous condition. Persistent patches or other changes in your mouth need a dentist's evaluation.It is Very Important you get a Biopsy done and confirm it is not cancer.If you are a tobacco  chewer you are or may be in some mess do not delay any chronic get Biopsy done now.