Can you explain me the below rule:

That the distance between the place a person is and where Jumuah prayers is going to be held should not be more than 2 farsakh (11 Km) and it would be obligatory for a person who is at the end of 2 farsakh to join the Namaz. And similarly, participation in Jumuah prayers will not be obligatory for a person who finds it extremely difficult, because of rains, severe cold and so on. Does it mean if I leave within 11km and I have no excuse I must attend Jumah prayers or does it mean I must attend 1 in 3 jumahs or it’s not totally must until imam reappears

The rule regarding friday congregational prayer is as follows:
1- The friday prayer can not be organized in two separate places within the 1 farsakh ( approximately 5 km) radius. Therefore this condition not for participants rather simply it’s about or agonizing two Jamat’s in same area.
2- Praying Friday prayer is Wahib e Takhiri ( obligation which has choice) it means when someone has offered his Friday prayer not for him no need to offer Zohr Salat and if Zohr salat has been offered now Friday prayer can’t be offered with the Niyyat of Wajib ( but Yes with the Niyyat of Mustahab one can offer like travelers).
3- Leaving Friday prayer with any genuine reason is not allowed and it differs person to person so everyone should decide is it possible on not for him. If we can go to office in extreme cold weather or while having normal flu or cold and fever then why not be there in Friday prayer?

Yes it has said said Friday prayer was Wajib when Prophet (saww) and Aimmah (a.s) were present but during major occultation it’s not Wajib aini but it’s Wajib Takhiri but its Obligation has not completely changed especially when all conditions are meeting with a person to have participation in it.