Indianmandarins has reliably learnt that the MHA, which is the cadre-controlling authority of IPS officers, has been sounded by the top command that IG rank posts should be offered to 1996 and 1995 batch officers till officers of both the batches (empanelled officers of 1995-96 batch) saturate in terms of IG postings in Govt of India.
Reportedly, this may be the prime reason IPS officers beyond these two batches are being preferred for JS posts under the CSS instead of IG-level posts at the centre.