@Nithin currently? No. Officially the title is owned by only 2 currently - Chiranjeevi in Telugu & Mammootty in Malayalam. In Hindi pushing for Salman after Big B as no other has earned that title.
Rajinikanth owns superstar title. So he would never be in the league of rest of the superstars as the moment "superstar" is used then it's Rajini, Period. Rest all come later and in that line would come Mahesh Babu who earned that title post Pokiri being industry Hit. His father owned the Superstar title and Mahesh had to prove his worth at the box office with Pokiri to actually be able to earn that title. Likewise King is for Nagarjuna so his sons didn't get the title, not even Prince as Mahesh Babu owned the title Prince until he proved his worth with Pokiri. So Nagarjuna in late 90s was called Yuva Samrat so his son Naga Chaitanya is given the same title Yuva Samrat, though truly he hasn't earned it. Ram Charan got the title Mega Powerstar [combo of his dad + uncle's titles] even before proving his mettle so he had to keep on proving himself to be worthy of the title [no other bloodline is worthy of that title] which he proved with Rangasthalam.
Either way, currently Indian cinema doesn't have 15 megastars let alone a regional industry i.e. Hindi film industry. Each big names have made their own place, like star of the millenium is Big B, Megastar is Salman, King will always be Srk, Ace is Aamir, Khiladi Superstar is Akki... Simple.
Like it is cakewalk to create 15 megastars within a single generation! Practically impossible.