Hi, I have to delete some pages from my website which are user generated. Will it impact my pagerank with google. will I get banned for delete some pages from my website. or google don't care about deleting?
Google doesn't ban for removing old content so don't worry about that.
It may affect your PR depending on how many people visit those pages and find them useful. If your site only has 5 pages and you remove 4 it will have an inpact. If your site has 10,000 pages and you remove 4 it will have minimal impact (if any).