First of all, I assume you mean a DDoS attack. A simple DoS attack would be ineffective and almost immediately dealt with by the server's firewall.
Second, a DDoS originating from a particular geographic region is almost as easy to block and would simply result in huge blocks of IP addresses belonging to Indian service providers being blocked.
The only way to launch an effective DDoS is to use a botnet with a large geographic distribution. However, this is highly illegal on many levels. Not only are you engaging in an attack which violates federal, state and local laws, you are also illegally comandeering and using computing resources belonging to countless private citizens, business, and even government entities (each of which is a separate charge of illegally accessing a computer).
Suffice it to say, this is the most illconceived idea I've heard of in a LONG time.
The BIGGEST problem in cyber security is not, as you might think, how to deal with cyber threats, but something called: attribution. In simple terms... who is responsible. If you own up to doing something like this, it would be like posting on Facebook that you intend to rob a bank because they short-changed you.