bitcoin it's not regulated there see india here
https://en.wikipedia.org/wiki/Legality_of_bitcoin_by_countrywhich mean that you are free to operate without tax, but it could not be the point anymore from this year(the wiki is not updated), if you can't ask locally it's better to declare your income to be safe
there must be also a maximum that if not surpassed it should put you in a tax free zone, but i don't know how in india things work
Thanks for replying. But it doesn't matter whether I declare it or not,the tax collecting authorities will eventually know from my bank account that I have received such and such amount from abroad and that could put be in legal trouble. So to be on a safer side I myself want to declare it but am at loss to figure out under what category should I show it.