I find it difficult to accept, that an aircraft could fly such a long distance, without ground radar detection....
My guess. . .third-world ATC. India. Awful. Only looking West towards Pakistan.
Could be (there goes that “possible,” “could be” qualifier) India didn’t want to be embarrassed by having a jet fly in from the east and transit their country and never be seen. . until it was too late.
With the amount of fuel it was carrying, even burning in to reserves, it would have made it there.
Was headed at one time for a route south of Sri Lanka and the southern tip of India where radar is probably sparse - cause there ain’t nothing out there in that huge Indian Ocean for them to be concerned about......