I really don't know how they legalize or i-legalize such thing as bitcoin because you are using it with your own internet and computer hardware maybe they just not supporting it before but every citizen of India can use it no matter what happens unless their government issue a criminal liabilities in using bitcoin.
The legalization and taxation side of Bitcoin does not appear when you are just trading Bitcoin from person to person, or just selling some goods or services to another person. However, it does appear when you look at businesses in real life that accept Bitcoin and exchanges that deal with Bitcoin. If you look at Australia for example, they just changed their taxes so that there is no longer any double taxation when you use Bitcoin, although, this never affected anyone who just did peer to peer trades and didn't purchase Bitcoin off an online exchange. I guess that is the same with the legalization of Bitcoin in India. It is now legal for businesses to accept Bitcoin and use it.
It's good to see bitcoin is approved by many countries. If all the countries accept the bitcoin means ,all the online transaction will be made by Bitcoin. Henceforth the price of bitcoin will keeps on increase day to day.Then we can use bitcoin as a legal currency. At last bitcoin will replace the dollar.
Yeah it really is great to see more countries accept Bitcoin, however it doesn't mean that all online transactions will be made with Bitcoin. There are still huge players in the digital transaction market such as paypal, skrill, paysafecard and a lot more. It will be quite some time before we see Bitcoin become a large player, if it ever does happen.