which are its major tributaries?
Alaknanda, Dhauliganga, Nandakini, Pindar, Mandakini and Bhagirathi.
Ganges
 The six headstreams are the Alaknanda, Dhauliganga, Nandakini, Pindar, Mandakini and Bhagirathi. 
what do you call ice falling from the sky Hail or sleet. how is it formed? In strong thunderstorm clouds,with intense updrafts, high liquid water content, great vertical extent, large water droplets, and where a good portion of the cloud layer is below freezing . what can be the size of this solid sleet? Their size is determined by measuring their diameter with a ruler or comparing them to coins. can they cause serious damage? Yes, to automobiles, aircraft, skylights, glass-roofed structures, livestock, and crops any incident related to the damage cause by this natural phenomenon? One of the earliest known incidents occurred around the 9th century in Roopkund, Uttarakhand, India. how did the state mentioned above get its name? From the Sanskrit words "uttara" meaning 'north', and "khaṇḍa" meaning 'land', altogether simply meaning 'Northern Land'. is there any pilgrimage site in the place mentioned? Yes, at Badrinath and Kedarnath. which are the different mode of transport in this state? Roadways, railways and airways. does the place have major rivers? Yes, the Ganges and Yamuna. from where does the first river begin its course? Gangotri Glacier. what marine creature likely to found there? It has been estimated that about 350 fish species live in the entire Ganges along with crocodiles, turtles and dolphins. does the river has any religious significance? Yes, the waters are purifying and wash away sins.
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Ganges [SEP] Course
Although many small streams comprise the headwaters of the Ganga, the six longest and their five confluences are considered sacred. The six headstreams are the Alaknanda, Dhauliganga, Nandakini, Pindar, Mandakini and Bhagirathi. Their confluences, known as the Panch Prayag, are all along the Alaknanda. They are, in downstream order, Vishnuprayag, where the Dhauliganga joins the Alaknanda; Nandprayag, where the Nandakini joins; Karnaprayag, where the Pindar joins; Rudraprayag, where the Mandakini joins; and finally, Devprayag, where the Bhagirathi joins the Alaknanda to form the Ganges. After flowing for through its narrow Himalayan valley, the Ganga emerges from the mountains at Rishikesh, then debouches onto the Gangetic Plain at the pilgrimage town of Haridwar.