I want to make an indie game for xbox360 . even if it is freeware I should pay Microsoft or not? And what will I need to develop an indie game
XNA Creators Club has a lot of the information you need to get started.
Check out XNA.
If you wish to put the game on Xbox Live which you do, you'll have to pay a small fee. About $100/£50 etc... Not too much. If you wish to just play this game yourself on your 360, then you won't have to upload it, though naturally no one else can get at your game. Check out this answer of mine, regarding XNA distribution. Depending on your scenario, you can get the fee abolished. Note for Windows development, there is no fee.
You'll need to write the game using C#, and the latest version of XNA at the time of writing is 3.1. The process is peer reviewed, as well as having Microsoft check your game. You must therefore complie with a string of rules and regulations.