Vishaal is, among defence circles, the unofficial name for the IAC-2 class. Which is the 65,000-ton nuclear flattop.
Vikrant-class is the IAC-1, the 40,000-ton conventional STOBAR powered by gas-turbine engines. So far only one ship of this class has been envisaged & constructed, the Vikrant you see being fitted out at CSL. Any further ships of the Vikrant-class haven't yet been confirmed or even officially considered, let alone named!
Once the nuclear carrier's design has been finalized, there could be a maximum of 4 ships of that class. A minimum of 1 and as per that guy PARIKRAMA's sources, 2.
No country in the world starts building a new carrier-class each decade once a matured design has been attained. Such an endeavor will be an economic & logistical nightmare. There will be no other class of aircraft carriers after this nuclear one - not until the time closes in to replace these carriers sometime in late 2050s or 2060s. This itself will be the ultimate, matured Indian carrier design.
What could come by 2030s however, will be additional ships of this class. Later ships of the class will be incorporated with newer technologies like radars, SAMs etc. These techs will also be implemented on earlier ships of the class through Mid-Life Upgrades if possible.
That is just my educated opinion.