if I've created account/wallet on coinbase or any other exchange then my account is hacked and my coins/money lost who are responsible for it
The Exchange where I've created account

is it my mistake

what's you thought about it

and how i make my account safe

the answer is quite simple. If you didn't follow the security instructions given by the stock exchange and you're hacked for that, you're responsible. but if you have followed the instructions, but the hacking took place, the responsibility rests with the stock market.