This forum is for the new model bikes with the unit-construction engine(UCE), which have the gearbox integrated inside the engine case.
The Bullet Classic forum is for the older pre-2009 vintage engine-type bikes made in India, which are often called the "Iron Barrel models". They were discontinued in 2008, and have the same basic architecture as the older British vintage models, with some small differences.
The AVL forum is for the recent bikes that have just been discontinued in about 2010. These were made for about 10 years, and were built in India, and the engine design was done by AVL of Austria, as an answer to meeting stricter emission control regulations. It was sort of an "interim engine" that fell in-between the older Iron Barrel engine and the new UCE, and has been replaced now by the UCE engines.
The AVL and Iron Barrel engines were produced side-by-side for a number of years, and thus there production years over-lapped here in the US from about 2006-2008 importation range.
The UCE is the only engine now in current production.
The Vintage Bike section is for any RE bike that was made a long time ago, twins or singles, and British or India manufacture.