Is it possible to earn 2-3 bitcoin by working online with out investing in an year or so...because i am not that financially strong to buy the bitcoin
You can sell some of your skills like content writing, photoshop, coding etc in exchange of BTC. Mining is also not practically possible without investment. For trading also skills and initial investment is required. Gambling also need initial amount and then LUCK. even your rank is too low to get any Worthfull work on this forum. So practically it is not possibly to earn 2-3 BTC in an year.
In current situation only but giving your skill for bitcoin and trading will give you atleast 1 btc in an year you can earn without investing. Other bounty options are very hard to earn as the profit will be very less and work will be high.