They can however they have very limited flights.
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Redemptions from India to US start at 80k points with Vistara whereas most airlines are somewhere between 30k something to 60k, with most airlines costing around ~40k-45k points.
And from Europe to North America 70k which might be among the worst, or the worst redemptions you could do. I think the only airline that can beat such bad redemptions is Air France on several routes where they ask north of 150k sometimes even 200k.
So in short it is a TERRIBLE redemption if you can even find an CS agent who knows how to do it and if they can find availability.
I did try redeeming with SIA to several destinations in SEA and the availability for redemptions with CV points on SIA metal was abysmal, sometimes nothing for months.
My advice: save those points for another occasion.