If there is an unanswered old question, how I can make it reviewing by people? My reputation is low, so I can't put bounty on it! Can I ask it again?
1You can drop by chat and ask people to take a look– Sathyajith Bhat ModJun 21, 2014 at 4:11
You can earn rep and then put a bounty on it– Oliver SalzburgJun 21, 2014 at 7:58
As was pointed out in the comments, your options are:
earning reputation by helping others and then invest that reputation into bounties on the questions you care about.
discuss the question with others in chat or share the question with people you know on other platforms.
edit the question to improve it. When a question is edited, it will be bumped to the front page again. An improved question can attract new answers from people who couldn't previously help.