Hello sreemooye ,I will be happy to answer your travel query🙂. per your query of epass needed from Bombay to go aor not ,I would like to say that you must apply for epass as you will be entering different state and its required for permissions needed to travel to another state .even if it won't be used but you must have all these important documents ,in case of emergency or any such thing,if asked and you have it then it will be safe but in other case if you don't have passes and other important documents,there could be some serious measures which will basically bring a bad memory to your trip .This it's safe and preferable to have epass already with you .And if you haven't booked anything yet you can check this link once. I checked online and found that there are some great deals available here.
https://www.tripoto.com/goa/tour-packages HAPPY TRAVELS
Yes definitely. you are entering a different state. and u need epass which is like a permission from one state's govt authority so it lets you travel in their teritory. so you gotta take e pass if u travelling from mumbai to Goa.