Char dham is called as four abodes which covers Haridwar, Yamunotri, Gangotri and Badrinath. These four Dhams is called as paradise which is done once in lifetime. On the other hand Do dham covers Badrinath and Kedarnath. If you are planning for once a lifetime spiritual travel I would suggest char dham. Of course you have to consider cost, stay, and travel expenses. June month is called as downpour month of Uttarakhand where showers, rains leads to landslides. The best time to travel to Chardham and do dham is before winter and just after rains say between September to November.