I’d like to use whole grain basmati. What changes in the recipe should I make?

No need to change much.
Since the rice cooking method here is like that for pasta (boil in lots of salted water until al dente, drain, use), no need to change measurements.
Rather, it will just take a little longer to cook the whole grain basmati.
Taste and test, the tajd rice off the heat when done.
Proceed with rest of recipe as written.