I have a flight from India to Frankfurt and Frankfurt to London via Lufthansa. I have a layover of 1 hour and 25 mins. Is this enough to connect? I am travelling with an Indian Passport.
If the airline is willing to sell you the ticket they believe you can connect -- because they're on the hook for rebooking you if you don't make it.
Further, there are plenty of flights to be rebooked on -- on the random October date I just searched for, Lufthansa alone has fifteen non-stop flights from Frankfurt to either Heathrow or London City, spread out over the day. So no matter how late your incoming flight is, you can expect to be on a flight to London with at most a few hours wait in Frankfurt (unless you miss the last flight of the day, in which case you'll have to wait for an early-morning flight the next day). It's not like some other connections where missing your flight could mean you have to wait for the same flight the next day.