As I have said in the title..
How can I send/receive GHs/THs on hashflare ?? is it possible ?
It is possible.
1st option: buy it on Hashflare. You receive the hashrate you paid for.
2st option: when you find someone who is selling hashrate, you can pay him and he sends an email to Hashflare to transfer the hashrate to your account. There are several offers available on this board right now. You only need to create an (empty) account on Hashflare before buying.
And the other way around:
If you have some hashrate you want to sell, then you can transfer the hashrate to the person who is buying it from you.
For the second option I suggest to use some escrow (a trusted third person), because Hashflare only transfers hashrate, they don't escrow for you.
You can only transfer contracts, so if the seller bought a contract of 100 MH/s he's only capable of selling 100 MH/s to you. However, if he bought 100 times 1 MH/s, then he can sell each MH/s seperately.
And then the final comment:
Cloudmining isn't a good investment. You may or may not reach ROI, and if you reach ROI it will take a very long time. Hashflare is a legit company, so the chance you're going to be scammed is small, but it isn't a good investment. (Only second hand hashrate has been sold for reasonable price, the price on Hashflare itself is overpriced in my opinion)
BTW: did I already tell you it is not a good investment?
Available hashrate AFAIK:
https://bitcointalk.org/index.php?topic=1832451.0https://bitcointalk.org/index.php?topic=1876754.0https://bitcointalk.org/index.php?topic=1877750.0