Hey Rosel, Rishikesh is an all year round destination to visit ... The best way to reach from Mumbai would be .. Board a flight to Delhi ... take an over night train to Haridwar from Mumbai ... and then only 20 Kms from there you will be in Rishikesh ... or else Dehradun flight is also dre ... but that will be a little costly ... from Dehradun you have buses and the journey takes hardly 3 hrs ... Happy Travelling Bro!!!