I need a java jre 32bit version, how can I install it in my Ubuntu Server 18.10? I could only install the 64bit version of jvm.
After java 8 there is no more 32 bit Oracle virtual machine. I think the same is for OpenJDK. You can search if you want for another virtual machine which has 32 bit and after that install it.
For example I see that Azul has 32 bit machine. But honestly I never test them. Maybe there are other JVM providers with 32 bit machines: https://www.azul.com/downloads/zulu/zulu-linux/
By the way I also don't know what kind of licences they have.
Apart from that Ubuntu 18.10 by default try to install OpenJDK 11. If you are OK with java 8 you can search how to install java 8 32 bits.