The two have earlier paired up for films including Hulchul (1995), Pyaar Toh Hona Hi Tha, Raju Chacha, Dil Kya Kare and U Me Aur Hum.
"We are working on something for Kajol but lets see if we are together or someone else. We should get the right kind of script to come together," Ajay told PTI.
"We are planning something but I can't talk about it right now. When the time is right we will talk about it. Whatever we work out we will let you all know... it is too early to talk about it," he said.
Ajay might produce the film as well. "We are planning a few things, lets see... it depends on a lot of things," he said.
The 43-year-old actor will be seen next in Sajid Khan's remake of Himmatwala opposite southern actress Tamannaah.
Kajol was last seen in a prominent role in Karan Johar's home production We Are Family.