The correct answer is option 2: 37°6`N. This option represents the latitude within which the main land of India extends. Latitude measures how far north or south a location is from the equator. The given latitude of 37°6`N indicates that the main land of India extends up to approximately 37 degrees north of the equator.

Options 1 (68°7`N), 3 (97°25`N), and 4 (23°30`N) are incorrect. These latitudes fall outside the range within which the main land of India extends. Option 1 is much further north, option 3 is even further north, and option 4 is further south. It is important to understand that India`s main land is located in the northern hemisphere, so latitudes south of the equator (option 4) do not apply.