I am planning to buy a domain with keyword "Android" to my website. But i am worried about having any legal problem doing this. If i am buying what all things i have to look forward?
Based on this text https://developer.android.com/legal.html it seems that you can't use the Android name in any way that goes 'beyond describing it as being intended to use with the Android platform' (which I agree is sort of vague).
I suppose, therefore, that it depends on how you are planning to use the name.