3rd battalion rifle brigade 1860

Hi,
Would someone kindly advise on how I may find out about an ancestor who was in the 3rd Battalion rifle Brigade in 1860, please?
I'm looking to find information on a private William H. MITCHELL who was in India & registered his son's birth in Agra, India in Jan 1860.
Advice as to how I might find out more on William's army history/career & where he may have been born/recruited would be very welcome.
I cannot get down to Kew, so any information is appreciated.
Thanks in advance,
Sandy
Would someone kindly advise on how I may find out about an ancestor who was in the 3rd Battalion rifle Brigade in 1860, please?
I'm looking to find information on a private William H. MITCHELL who was in India & registered his son's birth in Agra, India in Jan 1860.
Advice as to how I might find out more on William's army history/career & where he may have been born/recruited would be very welcome.
I cannot get down to Kew, so any information is appreciated.
Thanks in advance,
Sandy