Every year, we see a lot of films releasing. But, not every actor gets a release every year. For example, Kamal Haasan and Rajinikanth missed out on releasing a film in 2017. Ajith didn't have a release in 2016 and so on.
But 2018 seems to have a different story as all the top actors in Tamil Cinema have a film releasing sooner or later. Here is a list of films that the top actors are a part of:
Superstar Rajinikanth has Kaala releasing on April 27 followed by 2.0 in October, and the untitled film with Karthik Subbaraj in late 2018.