Next week i am planning to visit dubai, Do we need to pay any import duty/tax if i can get one from dubai duty-free shops, if i need to pay duty in india how much it could be.
This point has been answered in many posts and there are threads with detailed discussions on Customs and Tariffs.
If you are coming from any port outside India, the rules are the same. You are allowed upto 20,000 of duty free import. The catch is if you cross the 20K, everything is dutiable including the 20K. Customs rules are very vague and can be represented any way the officer on duty likes. The issues is simple - ultimately you can quote the rules and get your item, but the officer can confiscate the item, and it will take a long time to get it back. Duties on electronic items are upto 40%.
That was the dark side of Indian Customs.
The bright side is that most duty officers at major airports are not even bothered nowadays. The best would be to go to Red Channel, declare your item, say it is for personal use, and walk away with a small duty. In places like Dubai, some dealers will give you a second invoice dated nearly a year earlier and for some low value. If you get this invoice, the authorities cannot levy any duty as the item has been in use for a long time with say a brother, cousin or some such relation. You can mention that you have been gifted with the item.
Chennai Airport is a cake walk. You can actually carry an amp or an AVR and simply walk through the Green Channel.
Please search for and browse through the other threads.
A troubling issue is usually the weight and size of large items. Check with your airlines on baggage allowance before pick an item.
Cheers