Ok, as usual Airtel seems to have made a mess of this.
1. Airtel base packs - They always include DD channels, so they don't add another 25 to the total count. And in the total channel count under MYOP, they are excluding 4 or 5 channels from the NCF slab, I think it's depending on the number of HD channels in the base pack.
2. Airtel mini packs - They are excluding 31 channels from the count instead of 25. For instance if we select 104 channels, the channel count under MYOP shows 73 and the NCF shows 153. This is fine. Apart from excluding DD channels, they are excluding an additional 6 channels from the NCF slab, which is what
@Choco7905 stated earlier.
3. Normal bouquets/al-a-carte - They are excluding 7 channels from the count, but charging full. For example if we select 103 channels, the MYOP says 96 channels, but NCF shows 176 i.e. for 103 channels.
It's all very confusing and doesn't make any sense.