While no tooth paste can guarantee that you wont get cavities, there are some tooth-pastes that can reduce your risk of getting cavitits.
Colgate Maximum Cavity Protection - Colgate-Palmolive India Limited.
ToothMin Tooth Cream - Abott Pharma
ClinPro Tooth Cream - 3M Oral Care
The above definitely will ensure that enamel is protected from acid environment. However, even with the above toothpastes, you still will have to brush twice a day and floss. Watch your sugar-intake and avoid sticky sweets when possible. Avoid having sweets as a snack, have sweets with your meal. Finish your meal with durd/buttermilk rather than dessert.
Please Get back if you need any other information.