What major characteristic of India hindered nationalism during the British Raj?
The major characteristic of India which hindered nationalism during this time was its diversity. India was diverse in a number of ways. There was political diversity, with power being split up between many small states. There was ethnic diversity. There were many different ethnic groups speaking different languages in different parts of the country. Finally, there was religious diversity. The most obvious example of this was the presence of Hindus, Muslims, and Sikhs all in the same country.
It is easier for nationalism to arise when a country is homogeneous. India was not and this hindered nationalism.