Resign without offer

Can I resign without offer in hand? How to apply so that I don't even miss the chances of my profile viewed by top product based companies and not getting shortlisted due to my notice period? How much time on average does it take to land a job if not lucky in Analytics domain for 4 year experienced person with key skills as SQL. Please would be grateful of anyone could explain in detail and help me through the process or if someone has already tried and tested and could tell the pros and cons of doing it. Thanks in advance!