Answer for "i did my graduation with zoology hons. with 2nd div. what should i do nw?"

Hi, whether you do a post-graduation or not, you should decide the area that you wish to work and excel in – be it entomology, anthropology, ornithology, paleozoology, or cetology etc.
The best study option after completing B.Sc. is to complete a master’s degree (M.Sc, Ph.D., or M. Phil.) in zoology from a recognized institute.  Since you have 2nd division, you are eligible for these provided you clear their entrance tests. The chosen program should preferably be a full-time residential course for maximum career growth. Colleges will also assist you in job placements.  
Depending on your academic level, scores, and interests, you can look for jobs in various organizations like zoos, research centers, forest departments, marine parks, museums, government departments, conservation clinics, biological laboratories etc.