1. You need to find out nearby places (villages) /landmarks and then upon reaching there, locals re the most helpful. 2. State tourism websites also help sometimes. 3. Travel books (like lonely planet etc) are sometimes very helpful, as they have some really useful information. 4. Nowadays, travel blogs on websites like you tube are a great source of information.
The best option is to reach the nearest available option on the map and get directions from locals., .putting the location on insta also shows people who recently visited such un named places.,..,can ask direct help from them too.