Duty Free Allowance and Entitlements for Travel to India
Duty free baggage allowance rules are different based on the country of residence, duration of stay abroad and duration of stay in India and a few other factors. Please follow the links below for the category applicable to you:
Allowance Pooling
Duty free allowances of two or more passengers can not be added up (pooled or combined) to bring more goods duty free or pay lesser duty. Therefore, if one passenger brings a high value item that is above the duty free allowance, the passenger needs to pay the duty above the allowable limit, and the duty free allowance of the other passengers can not be used for the same. In other words, each passenger is considered to be traveling separately with his/her own baggage and their duty is assessed on an individual basis, not on the basis of a group or a family.

Reimport Items
In addition to the above allowances, items taken out from India by declaring them to customs after procuring an "Export Certificate" area also allowed to be brought in duty free.

Value of Goods
The duty is assessed on the value of the goods rather than the amount written on any invoice produced. Customs have a database which is used to assess the value. Therefore, if you try to underdeclare the value, it does not work.

It is a good idea to have your receipts handy to prove the price you paid for the items. If you bought a high value item at much lower price at sale, the lower value may be accepted if you can show the evidence such as original bill and the price list at sale etc. However, if you paid any tax on the item (such as sales tax), the duty will be considered on the entire price you paid inclusive of tax.

In any case, do not try to bribe a customs officer to avoid or reduce the duty.