Upvote:3
Speaking particularly for restrictions in India - any restrictions in place applicable to people arriving from UK would be applicable to you even if UK is a transit stop in your case. What you might additionally want to consider are how the state restrictions differ in India. For example for people arriving from UK I believe Delhi currently has no mandatory institutional quarantine if provided with a negative Covid test result whereas Mumbai mandates hotel quarantine.
Upvote:5
If your itinerary transits through the UK, or through the Middle East, or both, the cited document indicates the greater restrictions apply to you.
The identity of the air carrier(s) has no relevance.