Can I find 1 BTC? Which device I need to buy for this. And how long can I find 1 BTC out.
I know we need to invest a lot in mining. But I want to know what to do for 1 BTC.
You can get 1BTC with virtually any bitcoin mining ASIC, but 1BTC in profit is another thing. first we need to know your electrical rate, if it's above .1$/kwh bitcoin mining will be very difficult to accomplish. On the other hand, if it's near 0.02 or something lower then you can make a lot more profit; as of now, if your electrical cost is between those two rates, try considering the A721 from Avalon or the Bitmain Antminer S9.
I am new though, do you mean a PC running A721 processor from Avalon? Or what?
Defenately not a PC, leowonderful means an ASIC... An asic is a seperate device made for the specific purpose of creating sha256 hashes (or scrypt hashes for scrypt asics). Some asics do need a controller, other ones can run straight out of the box.
https://en.bitcoin.it/wiki/Mining_hardware_comparisonLike leowonderful already said, at this moment, it's allmost impossible to make a profit unless you have really, really cheap electricity and use the lastest gear (an A721, an antminer S7 or an antminer S9).
All other ASIC's are allmost obsolete. If you have free power, you might consider older ASIC's as well, especially if you can get them (allmost) free from somebody in the same country (to avoid custom duties)