Can anyone suggest me How to select a domain name and Which is best?
Keep it simple, keep it short and easy to remember, preferably .com if an international site …
Select a name best suitable to your purpose of the website.
Good luck
Generally, people put too much thought into domain names. Does anyone here think that Microsoft, Google, Oracle or Apple would have been any less successful if they had chosen another name? The same is true for websites. 
To add to ralph.m’s great suggestions, I would say it should be easy to pronounce.
Just have it be your company/site’s name with a .com. It is pretty simple. If you over think it and overly complicate it, it will show.
+1 …and in the language of most of its intended audience.
Around here a lot of hotels and guesthouses have Gaelic names. A friend of mine used her guesthouse name as her domain name, which seemed sensible at the time. However, part of the name is “Sith” (pronounced “Shee” - Gaelic for “quiet” or “peace”) and according to Google Webmaster Tools, her site mainly comes up in searches for Star Wars, rather than accommodation!
Firstly you should know that for what purpose of domain making, for education, as commercial, for business, In which way you have required a domain.Secondly you have to check the availability of your domain name. For business you can use .BIZ. for Education you can use EDU, For commercial you can use .Com. It depends upon your business.
keep it simple to remember.
top level domain like .com (if you are targeting in many countries)
If you go with proper country wise so go with (.co.uk if united kingdom) means country level domain.
use your domain name without “-” or “hyphen”
it will give you more benefit.
niteshahir brings up a good subject. From an SEO point of view the TLD can be important if you target a certain country:
I always recommend you registering domain name with COM domain name extension. Also your domain name should include your business name (or at least abbreviation) and be as short as possible.
Pick something that’s definitely short easy to pronounce, read, spell etc and is most apt for your business. It’s always best to go for .com and most of all - register the name quickly before someone else does! Also while registering, do it for a long period of time. You end up spending more if you constantly need to renew it…
Domain should be short and memorable.Good pronunciation helps a lot.If your users/clients are from world wide, you better take .com else you can register your ccTLD (.IN ,may be in your case)
It’s so simple; when you going to choose any of domain name for your business. It’ll be better
!) If the primary key word in url.
!!) shorten for easy to remember.