You can go for bleaching

Hello sir, you may start with scaling, but if you want permanent results you may try resin infiltration which are showing very good results in permanently treating discoloured teeth.

Scaling followed by bleaching if  not satisfied . Cost may vary from 10- 25k

Normal tooth colour is yellow.... Not white. So if it's pale yellow don't panic. U can go for a round of scaling. But if it's stained ....( Flurosis).... Which u can get a checkup done- u will need bleaching. It costs from 5- 20 k

First of all you need to share the pics that what type of stains you have then you need  to go for scaling to remove the extrinsic stains, but if there is flourosis then you need to go for bleaching or after scaling  u find it unsatisfactory then you need to go for bleaching. Bleaching cost varies like for front teeth upper lower it starts from 10k -15k approx. Consult the dentist to know the proper steps for whitening your teeth.