Send Data from local .Net application to AWS MSK?

Hi.

You can enable public access to the cluster after creating the MSK cluster.
Then you can connect to the MSK broker node from the client application via the public internet without connecting the local and VPC using a VPN.

You must meet some conditions to activate.

• Public subnet
• Secure authentication and encryption are introduced

See below for details.
https://docs.aws.amazon.com/msk/latest/developerguide/public-access.html