From 1757 to 1857 , the East India Company used a variety of political, economic and diplomatic methods to annex Indian kingdoms. the subsidiary alliance was one such method.
According to the terms of this alliance :

1.) The Britishers as a supreme Power:
which our state wanted to sign this treaty , had to accept the English as a supreme authority.The East India Company behaved as a guardian of that state.

2.) Appointment of resident :
The state had to keep an English resident in their court, to check the activity of the king.

3.) Keeping of an English army : Indian rulers were not allowed to have their army 2 protect the state from external and internal invasion.The state had to keep an English army.The state had to bear financial burden of the army.

4.) Giving to the territory :
if the Indian rulers failed to make payments, part of the territories were taken away as penalty.

A system where Indians had to accept all the command passed by British in return of protecting them