I hope you get good sleep along the way coz this might take long
There are direct trains but no direct flights for this journey. Travelling by train is the cheapest way of getting there. Chennai (Tamil Nadu) to Nashik (Maharashtra) distance is 1400 km and you can get there by train in just over 17 hours and 21 minutes. However, flight + cab tickets come also cheap with fares starting from ₹ 6131.
Beautiful weather for sightseeing and other outdoor activity.