Oh god lol it's like the Battle at Thermopylae with the Spartans and Persians, except instead of 300 vs. 300,000 it would be 100 vs. 100,000. It's the same ratio, so you would think the Rangers would lose, but perform greatly and die with honor just like the Spartans, yeah?
I'm afraid not as the weapons, tactics, and armour are way too advanced for the Redcoats. With zero or minimal armour, the Redcoats would be torn to shreds with their tight formations and heavy exposure. Let's say the Rangers just had a few tanks. I can almost guarentee not a single musket round would penetrate the armour specifically designed to withstand low caliber bullets, such as the musket rounds.
In summation, though enemies would seem almost endless, the immense firepower and armour of the Rangers, paired along with the poor tactics, accuracy, and armour of the Redcoats would lead to an immenent victory for the Rangers, or about any modern-day army in fact.