Since we would be discussing only 'What we are told" then I think the mentioned radar coverage of SU-30 at a flex on Aero India leads to the following calculations.
BVR, Head-to-Head:
The Frontal RCS of F-16C: 1.2m2
The Frontal RCS of Su-27/30: 10m2 (Thank the God for not making it 20m2)
Maximum effective detective Range:
AN/APG-68 V5 (F-16 MLUs): 70~80 km for RCS = 5m2 target
AN/APG-68 V9 (F-16 Block 52s) : 90~105 km for RCS = 5m2 target
AN/APG-80: 130km for RCS = 5m2 target
N-001 (Su-27S): 80~100 km for RCS = 3m2 target
N-001 VEP (Su-30MKK2): 90~110 km for RCS = 3m2 target
N-001 V (Su-27SM): 135~150 km for RCS = 3m2 target
(AIR INTERNATIONAL, 2004, Jan)
NO11M Bars (SU-30MKI): "140~160 km for an F-16 target"
(
The Su-30MKI Info Page - Vayu Sena)
Theoretically,
# The maximum effective detective range for AN/APG-68 V5 to detect Su-27/30 is about 85~95 km.
# The maximum effective detective range for AN/APG-68 V9 to detect Su-27/30 is about 110~125 km.
# The maximum effective detective range for AN/APG-80 to detect Su-27/30 is about 155 km.
@ The maximum effective detective range for N-001 (Su-27S) to detect F-16C is about 64~80 km.
@ The maximum effective detective range for N-001 VEP (Su-30MKK2) to detect F-16C is about 70~88 km.
@ The maximum effective detective range for N-001 V (Su-27 SM) to detect F-16C is about 105~120 km.
@ The maximum effective detective range for NO11M Bars (SU-30MKI) to detect F-16C is about 140~160 km.
BTW its pretty even. No?
And iam still assuming the RCS of MKI to be 10 since the F-15s RCS is 11 and these two birds are pretty similar in design and size.