@Omar Al-Deek
"Jamahir- why is India against China and why is India aligning itself with Western imperialism?"
The main reason for those is because of the ideological difference of the ruling BJP Indian government ( religion-based - Hindutva, extremely capitalist ) and the Chinese government ( communist - if only in name ).
But there are three confusions :
1. It's not as if the previous Congress party governments since Independence in 1947 have been socialist / communist. Though the first PM Nehru was inspired by socialism he did two things contrary to that : (a). Made India to participate in the Korea War ( 1950-53 ) on side of the "United Nations" militaries led by USA, (b). Co-found the NAM ( Non-aligned Movement ) which signaled to the Eastern Bloc that though India wouldn't henceforth participate in Western military adventures India wouldn't also participate in any action of the Eastern Bloc ( Warsaw Pact ) and wouldn't close cultural, diplomatic, technological and economic ties with the Western Bloc.
2. Nehru's daughter Indira Gandhi, also of the Congress party, when she was PM reworded the Indian Constitution's preamble to become "sovereign, socialist secular democratic republic". However, not only was "secular" not implemented practically in the country, "socialist" was also not implemented through things like free housing, education, medical system, public transport etc and other things like shutting down of the Bombay Stock Exchange.
3. Another Congress party PM, Manmohan Singh, said in 2009 that the biggest internal threat to India is not the right-wing, Hindutva movement but the left-wing Naxalite / Maoist guerrillas. You can read that full statement
here.
Other than these, the Indian establishment and military has always been pro-West or West-inspired. For example, the chain of government-funded, elite education institutes called IITs ( Indian Institutes of Technology ) are modeled on the American MIT. The Indian penal code has been continued from British-rule times, including the "Sedition" laws which were instituted by the British to jail Indian freedom fighters including left-wing revolutionaries like Bhagat Singh. The Indian intelligence agency RAW has had close ties with Mossad going decades back.
Though India and China fought a border war in 1962, in recent decades India and China had had economic ties with things like Chinese cell phone companies or firecracker companies selling in India, or Chinese civil engineering companies sending huge tunnel boring machines to India for various civil works. These economic exchanges happened despite India's BJP ruling government being ideologically different than of China but they have stopped now.
The current antagonism at the India-China border is continuing on the Indian side, the BJP government not speaking of dialogue, because the BJP doesn't want to step away from its hypernationalist position and alienate its middle class and upper class mainly Hindutva constituency. This is added with the Western governments' position of using as a regional bulwark against the expansionism of rival-to-West China. There is the anti-China military alliance called Quad consisting of India, USA, Japan and Australia.
Did I miss out any of your queries ?