Except that the situation is not similar to Mekong River. Brahmaputra flow through only 2 Indian states,Assam and Arunachal Pradesh. 90% of Brahmaputara's water comes from territory outside Tibet. North Eastern India is one of the most wettest places on this planet and Arunachal and Assam receives more water than it can ever consume. May be you should learn a bit about geography and learn about Himalayan mountains and Indian monsoon. Unlike Thailand or Burma, India's Himalayan territories gets monsoon, upwards of 3,000 mm an year, which contributes to much of Himalayan glaciers and water for Himalayan rivers.
India already building it's largest dam few kms downstream of Chinese dam, capable of holding more water than Assam and Arunachal can ever consume. Indian concern isn't exactly about China stopping Brahmaputra's water, they can't stop 93% of Brahmaputara's water simply because it's from outside their territory. China can't control downstream flow or cause floods, India has even larger dams just downstream. As for the sediments, well, they are supposed to settle in Bengal delta (east Bengal) not in India. Any sediments would have got caught in the new Indian dams anyway.
Biggest benefactor of Brahmaputara is not India, it's Bangladesh. They are the only one who is going to get screwed at the end. With Chinese Dams holding 6-9 BCM of water and Indian Dams holding another 9 BCM of water, they gonna get get hit bad. The entire country is practically river delta and they gonna have a hard time.