This from Microsoft after opening a ticket
From the following we understand that the latest version of the .NET framework which CRM 2011 is compatible with is .NET 4.5.2. We also assume that your server infrastructure is running on Server 2012 or lower as CRM 2011 is not compatible with Server 2012 R2 or higher.
https://support.microsoft.com/en-za/help/3005163/compatibility-with-microsoft-dynamics-crm-2011
This brings us to conclude a couple things. Based on the following article. It certainly is possible to enable TLS 1.1 and 1.2 (this answers your 'How?' question).
https://support.microsoft.com/en-us/help/3140245/update-to-enable-tls-1-1-and-tls-1-2-as-a-default-secure-protocols-in
Another consideration is the browser and OS compatibility of your clients for enabling these protocols. Below is a good reference for this:
https://www.applicationstation.com/home/CompatibilityGuidelines.pdf
We do know that this has never been fully tested for CRM 2011 as the protocol release was after our product release. With this in mind, the configuration is technically not supported, but it is entirely possible that they can be enabled without problem. We would, at a minimum, recommend full testing of any scenario enabling these protocol against a CRM 2011 environment before deploying it to production.