Well, it depends upon the country you are in and what documents you want, our travel history and stay in foreign land if more than 6 months then PCC from that county, so these things can take time since now rules have changed.
Earlier it was simple and easy for applicants as filling at CIO required just the forms and passport copy that is it and now it requires the complete copy of set and original PCC. Well this in long run will beneficial for applicants only.
Usually PCC's from other country's take time and original transcripts, rest can be done quickly.
Which country are you from
Which visa office will you select
Travel history and stay ?
These things will help me give you a better and to the point answer