I know If we invest in any International ETFs like MON100 or MAFANG or Mutual Funds it will be taxed in the same manner as debt funds @ applicable slab rates.
But if we invest directly through a foreign broker into US stocks or ETFs then 
Which will save more tax in long term - Investing directly through foreign brokers like Interactive Brokers or investing through International FoF/ETF like MON100 or MAFANG?
Let’s say I’m investing 7L every year and it gives me 20% CAGR for next 10 years.
Since you have already shared the taxation applicable in both the scenarios,
what information do you NOT have,
that you cannot calculate the applicable taxes for both the scenarios? 
taxation is applicable when you sell any investment? In this case, the above tax rules are current, who knows what rules will be applicable after ten years. I chose ten years as investment is going to be locked in for 10 Years.
I’m just confirming my info is correct 
In scenario 1, I’ll have to pay 30% of 14805292 = 4441587
In scenario 2, I’ll have to pay 20% of 14805292 = 2961058
Scenario 2 saves more tax. (4441587 - 2961058 = 1480529)
Ofcourse tax rules can change in future. But I’ve seen that they always mention that it will apply to people investing after a certain date.
Napkin-math checks out. Roughly.
Also, please do the math and plan for the stagnant / capital-loss scenarios as well
as that is more likely over the coming decade. 
