I went for walkin on may 2017. There was total 4 round. Initially GD for screening general topic like, women empowerment or childlabour or education system . Second round HR interview question were like self intro, why HGS what u knw abt HGS being a engineer why you choose this position. What u knw abt non voice and sme related question. Third round ws aptitude which includes English logical reasoning maths question was very simple and easy time allocation was 1 hour. You hve to score above 60%. Final round we'll be called fr another day.. Overall the interview was easy but go prepared. Long distance ppl they wont hire.