For PGDM HR, there is no specific cutoff but how much CET Marks shall be considered good to get PGDM HR.And what is the average placement?

Regarding hr there is good placement at dalmia as the batch size eventually turns out to be very small , and a score of around 100 is good for PGDBM HR

Yes as you mentioned.. There's no specific cut off for HR. But your selection will depend more upon how well you do in your Gd and PI. The average placement for HR is 4 lpa.