[GRASSLIST:7357] i.rectify: How to determine the resolution to be entered for the target location?

Hello,
I am looking to Geocode a scanned map into my GRASS location for digitizing.
In i.rectify

Please select one of the following options
1. Use the current region in the target location
2. Determine the smallest region which covers the image

I selected option 2

How to determine the resolution to be entered for the target location?

Thanking U

Regards

Nagesh V Bhatkar
Physical Oceonography Division
National Institute of Oceonography
India - Goa

Can anyone tell me what should be the resolution to be entered.