Colonial masculinity was used by the British to subjugate and manage their claim to India. Essentially, the British colonizers believed that they, by virtue of their physical strength and military/economic power—all so-called "manly" or masculine traits—deserved to be in charge. They promoted this sense of superiority and the belief that their actions in India were righteous. The British were the men for the job, as it were.
This was accomplished, in part, by putting down Indian men and calling their manliness into question. For example, an Indian man who attempted to become educated and insert himself into the British world might be labeled as "effeminate." Women, of course, were not considered equal partners, so any men seen to share womanly characteristics would be automatically ignored. The British Empire went even further, in 1878, by passing the Arms Act. This made it practically impossible for an Indian man to carry or use a firearm. Being armed and dangerous, able to use physical force to resolve conflict, was then allowed only to the British. Once again, this traditionally masculine practice was reserved for the colonizers alone.
It's clear that this colonial masculinity was not well perceived by Indians. They were understandably upset at having their rights limited. Furthermore, Indian men chafed at being put down in so many ways (what we now might call "microaggressions") by the English. All this simmering discontent eventually led to the civil disobedience movement led by Mahatma Gandhi and India's eventual liberation from the British.