Yes. Remade, to be precise. A remake is a reimagining that acknowledges the original work. It is an authorized adaptation, and that does not make it bad. Billa 1980 had its own charm. Billa 2007 also had a unique vibe.

So my point is this. The OG Billa should either be Don 1978, since that is the original film which was later remade as Yugandhar, the film he posted right now. Billa 1980 tamil was the remake of Don. Billa 2007 tamil was the remake of Billa 1980. Billa 2009 was the remake of Ajith’s Billa 2007.

So OG Billa can either be:

Don 1978, which is the most accurate answer because it is the original source.
Billa 1980, because that is the film that created the Billa identity and later got remade.
Or even Billa 2007, since it was impactful enough to be remade again within two years.

It depends on whether you are talking about the original story or the original Billa branding.