@RAGNAROK Not sure of exact details but brief overview of issue is
Some states were just saving CSS funds given from central share in Bank without using it & were earning interest from such saving instead of timely allocation to schemes within a particular period, leading to execution delays
To prevent this, centre has made Single nodal agency system mandatory wherein centre will give its share in certain tranches provided the states appropriately allocate funds for the respective single nodal account created for each scheme and utilise it
If state continues to do the old method of interest earning etc ,States should payback such interest earned to centre (ie., respective tab under consolidated fund of India)