Can anyone suggest me how could i upgrade my Bitcointalk rank? 
I suggest you continue posting but only post a constructive posts because it might be deleted by the moderator. Due to your post your activity will also add 14 activities but that is after two(2) weeks. Before there is no merit we just need for our activity to reach a certain number so that we easily rank up. But it is now different. We need to have or to earn merit(s) to rank up. If our activity is already for senior but our merit is just for full member, still we are full member.