Add a client install package 32Bit, what happens to 64BIT client

I have upgraded my SEPM to latest version 12.1.6MP5 and now need update all my clients. What I do is on SEPM click on Clients, choose required group and click on Install Packages tab. I then Add a Client Install Package. What I normally do is choose 32BIT package version.

I would like to know what happens to 64BIT client, do they also get updated or I need have 2 group one 32BIT and another 64BIT?

Any other way to upgrade all the clients?

Thanks