This etching is by Francois Balthazar Solvyns (1760-1824) and its entitled "A Sikh in a landscape: from A Collection of Two Hundred and Fifty Coloured Etchings Descriptive of the Manners, Customs and Dress of the Hindoos" (Calcutta 1799.)
Here's a description of the painting:
The figure depicted displays some of the symbols of membership in the Khalsa (the 'order of the Pure'), founded in 1699 by Guru Gobind Singh: namely uncut hair, a steel bracelet, and short breeches. (The comb in the hair and the short sword are concealed in this image). The dark blue colour of the cloak may indicate the figure's being of the zealous Nihang sect.
The etching is up for auction by Bonhams and yours to be had for £800 - 1,200.