Running Separate Instance under one elasticsearch

I have create ELK stack VM for my students and everything is working file except one thing. I sent logs from my VM through logstash in elasticsearch for analysis, created index in it. But if another student will do the same and send his own enriched logs in it, the old indices are visible to him. I want to say is that, if i create index in Elasticsearch, other are able to see it as well and when i delete it, it gets deleted from other students VM too when when look into the Elasticsearch. even thogh it is on localhost; localhost:5601/, the instances are not separate for everyone. any solution for it?

Thanks for reaching out, @Raj_Badhiwala. What version of Elastic are you using?