Where can I....?
You can get a regulator at any dive shop with a diving licence. Otherwise you might have trouble getting one. They are very expensive. Nitrogen cylinder might be at your local welding supply. good luck
Where i can get welding machine for hire in pune?
There are plenty of welding equipment companies in India, Check this website. then refine the search, you'll find what you're looking for.
How difficult is welding to learn/do?
Sorry - no propane torch welding! You can pretty much choose between Oxygen-Acetylene gas welding and electric arc welding. You won't learn to do either of these from a Vo-Tech school. Most Vo-Tech schools have gone to teaching only tig and mig weldi...