Yes, the introduction of Six Sigma is a major OD intervention, but it is not an HR intervention. It is the production or operations departments that benefit most from Six Sigma. A lot of material is available on the internet on this subject. You can educate yourself from the material available. If you wish to gain firsthand knowledge, then you may do some capsule courses or certificate courses.
In one of your past posts, you have written that you are an HR Executive. For your level, it is a slightly higher intervention. The introduction of Six Sigma is a management-level decision, and it is better left to them. Your past queries show that you are yet to develop a basic understanding of HR itself. Therefore, it would be prudent if you give priority to this field rather than making a foray into other fields.
All the best!
Regards,
Dinesh Divekar