For starters the factor of latency is quite sensitive and will depend from location to location so you'd definitely would need to do some scouting from providers in your area and you should also use the ripe atlas console.
Make sure the connection is you are getting is completely fiber upto the last mile that is your ONU device.
Latencies will usually be in this range from the following providers to EU from Mumbai Sea Cable.
Tata - ~200ms
Airtel - ~165ms
Sri Lankan Tel - ~220ms
Jio Sng - ~130ms
Sify - ~180ms
Tata while latencies are high, it is a more stable network since it's a Tier 1 ISP it has more control over it's internet routes.