Answer:
There are three major sets of negative influences that the British had on India.
Economical - They bled India dry, exploited Indian natural resources, market and labor while giving them minimal returns.
Political - They started the divide and rule policy, effectively creating an enmity between Hindus and Muslims and fanned the narrative that the two communities cannot peacefully coexist. The paranoia was of course used by the Muslim Nawabs and feudal lords who like their Hindu counterparts (Maharajas and zameendars) did nothing for their commoners. The partition, at least the way it was implemented by the British is another example of a political blunder, the burden of which we still bear.
Social - The British mistreated Indians, distorted their history and had them live as second class citizens in their own country for around 200 years. They believed that Indians were inferior to them and there are literally thousands of acts of atrocities that they had committed on Indians. People died in famines, British did not care, Indian soldiers died fighting battles for them, British did not reward. When they left, we were economically broke, socially divided, thousands of refugees on either side due to an ill managed partition. Luckily, for India we had secular leaders, who did not let the madness go on for much longer and luckily for India we joined NAM which paid back 30 years down the line.
