Courtesy: Uschi Ringleb (and GeoGebra- Makers of this simulation).
The calendar (application) below providse a good visual for a Luni-Solar Calendar. Be aware of the obvious limitations.
The calendar only shows Rashi (Zodiac) and not Nakshatra, which is the original Indian system (and still prevalent, although Zodiac signs are also employed).
The precision required for ‘Intercalary month’ does not exist.
Enjoy for what it is worth!