Welcome to True Path, an alternate universe My hero Academia RP set BEFORE the actual Series! We are at the beginning of the establishment of Hero society, come join us and help us create the wold of My Hero Academia.
I'll mimic what others have said for both of this characters. Of any two students at Yuuei, these two would be the most well known. Lani because of the events of the festival. A lot of students were there and it was the first major disaster since Yuuei starting up. ICly, everyone would be looking at Yuuei for something that was happening in their own backyard. All the students did great, but to capture the main culprit behind it all was outstanding. It would be something that everyone talked about.
As for Rin, she has pretty much met nearly the entire roster of students. Everyone has met her or at least knows who she is by proxy. Hard to argue with her being the most well known on a personal level.
Lani, as mentioned, became the first student to really stand out as a prospect heroine for the future. For that, she has my vote. Jasmine Noir has gained quite a bit of infamy, plus quite a bit of respect. There is no doubt, with all her altercations, that she is one of the most powerful students at Yuuei. Saviour or Scoundrel, remains to be seen.