Any Info On This King Rama V Thailand Medal?

Medallion. Rama V (King Chulalongkorn) often considered the father of modern Siam/Thailand.
The reverse you posted upside down. The little squiggly things are predominently on top of the letters.
So turn it 180 degrees and you have the RS date 116 at the bottom which is 1897AD.
Two important events relate to that year. One was his first grand tour of Europe to establish a Siamese presence on the international scene and was by all accounts a complete success.
The second was the hierarchical administrative reform of Siam. Land areas were established as Provinces then City, Amphoe, Tambon and Mhu Ban (village). The system still applies to this day.
I've had my (Thai) wife look at the inscription and she 'thinks' it applies to the land reform. She is not very good at Thai history and I probably know more than she does but then I can't read the language.
Now for the bad news. Rama V is the most respected monarch of Siam/Thailand and even today is accorded the deepest respect and held up as a demi-god. Therefore there have been probably hundreds of memorial medals struck in his honour for any number of reasons. Many of these are mounted and worn by Thai people as a good luck charm. You'll find any number of them for sale on market stalls that specialize in charms and Buddha figures.
Obviously the ones in gold and silver command the highest prices so yours in brass (as it appears to me) would not command a high price unless it was actually contemporary with the date.
That's the best I can do for you. Hope it helps.

By the way...welcome to the community.