Conditional Format Based on specific text in 3 different cells

I have the following code to fill Y2 based on the text in L2 or M2

=OR($L1="g",$M1="g")

I would like to add to the formula so that it would only trigger IF the text in C2 which is normally a number followed by a space and then a single letter (ex.= 23 A), has either "rt" or "rs" at the end. (ex. = 23 A rt)

Is this too many conditions to nest within regular conditional formatting?

Any help with this or an alternative formula would be greatly appreciated!

Thanks