Thanks for the reply, below are few details, can you suggest any thing more from them.
1) How many pages will you remove? How many pages will you have left on your site after you remove them?
We have around 180000 pages from whihch 8-10% of the pages will be removed.
2) For the pages you want to remove, what percentage of traffic do they get?
These pages get around 6% of the traffic
3)What will you do with those pages once you remove them?
We will redirect the pages to the home or the closest related page.
Also please provide reference threads if any from this forum regarding this issue which will be helpful for me.