Question

what were the reason that british colonise india

Answer 1

it is because they felt if India revolt then they opposed against them so they colonise india

Answer 2

Vascodagama was the 1st person who came to India for spices.
After him many people came to India.
Even Britishers came to India.
Britishers attracted to the species which were not available in there place.
They thought that , they can sell spices to gain profit.
Not only spices, textiles, etc
More over India has huge population, which they can earn more profit by establishment if industries etc...
They used Indian people as military power.
In this way Britishers gained many profits.

I hope this answer will help you frnd.
Tq
; )