"regi.exe" is available only from HANA Client for 64 Bit - Hence you cannot install the client in your machine. But, there is a work around:
You can go to AWS, and create a new 64 Bit instance for free (There are many micro instances that falls in Free tier).
Once you have a 64 bit windows instance up and running in AWS, you can install the client & studio in your new 64 bit instance, and connect to HANA Server.
Best Regards,
Gopal Nair.