Lankesh was shot dead at her residence by few unidentified assailants on September 5.
"Based on the information we have made the sketches, now we want cooperation from the people," the Special Investigation Team (SIT) chief, B K Singh, said here.
Singh further stated that they also have the video of the recce done by the suspects and they would be releasing it as well.
There are two suspects and the sketches have been made by two artists based on accounts of different eyewitnesses, he said.
Singh emphasised that they couldn't ascertain the religion of the suspects by their external appearances "like 'tilak or earrings' as they can be misleading too."
The SIT elaborated that they had investigated 200-250 people in connection with the case.
Lankesh was the editor of the Gauri Lankesh Patrike, a tabloid described as an "anti-establishment" publication.
Following her murder, several protests, across the country and especially in prominent parts of Karnataka, took place, leading to a stricter probe into the incident.