What is the age of this Ruud a/c

s/n M2400
model RCBA-2457GG14

Date of manufacture 24th week of year 2000?

It would have been nice if you listed the COMPLETE serial number, but if the section you listed is actually the date code section, then your guess is correct.

You will need the serial number or, most Ruud/Rheem units have the date stamped in the upper right hand corner of the data plate sticker.