Recommend a book/source for mixed problems of jee main for math

I will give full mock tests from March, till than thinking to do 25 questions of maths in one hour, any book or online portal?

As per your credentials you were from resonance, so you must be having the dpp booklet that the provide , right ?!
They contain really good questions and adding to that they are from mixed chapters , and by march it can be completed also , so i think that will be the best source that you can use now .