Tenant Not agreeing to permit anyone inside her flat to undertake repairs.

In our flats we have got a peculiar problem. A owner of a flat (2nd Floor 210) complained that his kitchen walls are getting wet due to a leakage in the flat right above(3rd Floor 310)theirs. And the damage to the wall ( paint peel off etc.) is increasing with every passing day. When he tried to tell the problem to the tenant residing in the flat 310, she didn't properly talk to him and to his surprise she said she would not allow any plumber inside her flat due to fear of Covid. He then escalated the issue to the owner (310) of the flat residing elsewhere. The owner (310) tried to convince their tenant the seriousness of the issue and told about the care and precautions they would take while carrying out the repair, still the tenant didn't budge. She said she would not come out nor let anyone inside till a vaccine is available for Covid! Infact she locked herself up along with his son (35) and grand son (15)in the flat. These three people have not come out of the flat since April 2020. She is ordering groceries and the watchman would put them infront of their door and then she would pick them up. She has not allowed even her daughter to enter her flat whenever she brings vegetables. So the owners of the two flats (210 and 310) are a worried lot as they are unable to find any normal solution. What is the legal course available in such circumstances for 210 owner and 310 owner.