To implement HTTP/2 support on nginx/1.11.1, I'm going to redirect all HTTP Request to HTTPS.
In this case, how will Bot and Browsers, that don't support HTTP/2 protocol, behave and render the page?
Is there a way for me to simulate HTTP/1.1 browser behavior on Chrome Developer Tools?
You are mixing two concepts here that are somehow related, but they are largely different: HTTP to HTTPs redirect, and HTTP 1.1 vs HTTP/2 negotiation.
Redirecting HTTP to HTTPS requests is fine. Virtually every client (browser, bot, etc) available these days is capable of understanding HTTPS requests.
As for HTTP 1.1 vs HTTP/2, Nginx will fallback to HTTP 1.1 if the HTTP/2 connection fails because the client doesn't support it.
Last but not least, this question has very little to do with StackOverflow. It is more appropriate in ServerFault or SuperUser.