This is of course possible with any major Registrar such as: eNom, Godaddy, Namecheap, etc…
Originally Posted by manojkumar7
No problem with this one. You can use only one domain and in addition you can also redirect the traffic from other extensions to .com domain if required.
From there, I would like to use only .com domain.
Theoretically it is of course possible, but very hard to predict. In addition if you own the .com extension the chances that other people would demand to have other extensions might be quite low, unless you become famous as Facebook or Twitter, but in that case I doubt you will consider selling other extensions.
Is it possible to sell other extension(.net .org .info) domains to a third party in future,say after 5-10 years?
All major registrars allow you to push each single domain from one account to another, so this is very easy to handle.
And, how to transfer domain name extension(.net .org .info) to third party which where bought under a packaged domain registrar? Is it possible?
Very hard to predict as indicated above. There are several large marketplaces for domain name selling such as: Sedo, Afternic. You can try your luck.
how much can I earn for selling
the domain name immediately and after 5-10 years? (if domain name is catchy/searchable)
I hardly doubt it, unless you develop the domain and receive significant traffic, which you can convert into Sales or sell Ads.
can I make money instead of selling it?
Imagination is more important than knowledge.