The core BI Platform Server & Tomcat only use JRE/JDK 64bit. If you are want to run WebI on the server than you will need to install JRE 32bit.
See detail step-by-step on how to upgrade JRK/JRE for BI 4.x Platform
How to update JRK/JRE for BI 4.1.x Platform
Regards,
Ajay