Interesting question.
The Russians would have faced IMMENSE logistical problems in deploying an army across Central Asia - Afghanistan was one hell of a roadblock, as the British found out - and it would be very difficult for them to get a creditable force into striking range of British India. It’s possible that Napoleon’s grand dreams could be realised - France and Russia unite, take over the Ottomans and Persians and then head to India - but they’d still be extremely difficult to get to work. Problem is, the UK controlled the seas and there’d be no way to get a large army to India by sea.
The Chinese would have to implement major reforms if they wanted to pose a threat to India - Hendryk can probably comment on that.
The Ottomans and/or Persia might be able to invade India, but - again - it would be hard for them to get an army into striking range.
It’s possible they might work to ally with an Indian force already there - the Sikhs, perhaps, or Afghans - but that would still require sending them arms and suchlike.
Chris