As mentioned in the title, my forefather served in the british indian army somewhere around the 1860s-1870s, and probably in the cavalry. how do i find his regiment as my main aim is to find out the medals he was entitled to (i'm doing this for all my family members who have served in the army). i live i New Delhi and can't afford to visit the British national archives in Kew, london for this specifc purpose, never mind the pandemic.

one major challenge that i am facing is how the names were spelled differently during the british raj in india and post independence. for eg: the Punjabi/Sikh surname 'Arrora' was spelled as 'Aurora" during the Raj

Any help would be appreciated