Yeast starter?

It has been a very busy last 3 week and did not
Have the time to make a yeast starter for my
RIS that I am wanting to brew. Can I get away with
Just using 2 vials of yeast?

You can “get away with it”, but you will get much better results if you make a starter. Better yet, make a lower gravity beer (OG ~1.045) first, then brew the RIS and pitch it on the yeast cake.

Have your run the numbers on Mr. Malty?

Saying you are making a RIS tells us very little.