What is the likelihood of getting Ranger School in the National Guard?

In the Guard only Infantry units have slots for Ranger School and they are limited. Sending someone on active duty for that long takes a huge chunk out of a units training budget. I noticed you are a 13B so if you stay 13 series then the answer is no. But if you are in a towed Artillery unit they do have Air Assault School slots because part of the light artillery mission is to be air assaulted by helicopter. When I was in a towed unit in the Guard we had 2 Air Assault slots available each year

As everyone has said it depends on your unit and state. However I know at my unit we have a SM that just returned from ranger school but my unit has a lot of SM enlisted and officer that have completed ranger school.

Slim to none, depends on the state funding and you have to compete in an OML to get school slots.

First, I would want to know how this would benefit my unit. Know the Ranger mission and you might find all that's gained by successfully completing the course entities you to display the tab. An infantry Guard unit would be an infantry unit with one or two Rangers.
On the other hand, participating in the Infantry school would enhance what you have already learned. And, your unit would greatly benefit from the extra training you receive from becoming an expert Infantryman.