Dr. Rakesh Kumar, Assistant Professor, School of Mathematics, Shri Mata Vaishno Devi University, Katra delivered an Invited Talk in the 4th National Conference in Mathematics on Mathematical Sciences and Applications at GGM Science College, Jammu during 19-20 January, 2018. He also chaired one Technical Session. Dr. Kumar discussed his ongoing research work on Queuing Systems with Retention of Reneging Customers. The audience enjoyed the talk and got very much interested in the applications of such queuing systems. It is hoped that some new research collaborations may take place in near future. Dr. Rakesh expressed his thanks to the organizers of conference for inviting him in this national meeting.