Steps are pretty straight forward and same for all the platforms, the thing you need to take first step:)

Here the document with installation and configuration steps.

OBIEE 12.2.1.0.0 Installing Oracle Business Intelligence https://docs.oracle.com/middleware/1221/core/BIEIG/toc.htm

OBIEE 12.2.1.1.0 https://docs.oracle.com/middleware/1221/core/BIEIG/GUID-04F89ACA-A2F1-4F18-8B35-BD131ACC62ED.htm#INSOA369

OBIEE 12.2.1.2.0 https://docs.oracle.com/middleware/12212/lcm/BIEIG/GUID-D5AFD830-8A7D-42CC-8C22-CE68C452CF4A.htm#INSOA369

Make sure your AIX machine is of version 7.1 or 7.2 as these are only supported AIX OS Version with OBIEE 12c

More generic Oracle Document with Screenshots

OBIEE 12c: Quick Reference For Oracle Business Intelligence Enterprise 12c (12.2.1) Installation (Doc ID 2064302.1)

Below link is for System Requirement for Oracle Fussion Middleware Products

Oracle® Fusion Middleware System Requirements and Specifications

For OBIEE 12c instllation on IBM AIX you will have to consider below points:

• AIX OS version needs to be 7.1(Update Level 1+) or 7.2(Update Level 0+) ,
• OBIEE 12c is only 64 bit OS supported
• IBM JDK 1.8.0 SR2 FP10+ (64 bit)
• Rest of the requirement like Processor, Network etc are mentioned in above document link in this post.