I am very worry about new merit system. This is like killer rules for newbies like us. As i know that if somebody gives merit rating only then our rank will grow.
Without getting merit from someone we can't rank up from jr member. So, who will give us those merit rating? Is this rules for avoiding new comers in bitcointalk? I am truly feeling too bad.

You only need 10 merit to reach Member. The Merit system has been around for just over a week, I've earned 20 merit in that time. You can surely earn 10 over a similar time period.
You need to make high quality posts. You need to introduce new information to the community. You need to join discussions in boards where higher ranking people (who have merit to spend) hang out. When you have good, new information to share with the community consider starting a thread so that more people will read and react to your post.
The merit system was not established to keep newcomers away (obviously, no one requires merit to join and stay here). The system was established to ensure that opportunities to rank up align with the contribution one has made to the community.