I am installing Appian 16.1 in Windows 12 R2 environment. Getting the following

Do you want me to check JBOSS_HOME in environment variables? I have that set up in the environment variables. Not sure where to look for this in configure script.

Did you use the configure script to setup Appian or the manual steps to make changes? If the latter, I recommend repeating the setup steps and using the configure script, which replaced the PS Build script.
1) forum.appian.com/.../Configure_Script.html
2) forum.appian.com/.../Configuration_Manager_to_Configure_Script_Migration_Guide.html
3) forum.appian.com/.../Quick_Start_Installation_Guide_for_Windows_and_JBoss.html

You can find JBOSS Path in <APPIAN_HOME>\\_admin\\_scripts\\configure\\.configure

Thanks for the comments. I redid the whole installation using configure scripts. At this time, JBoss starts up, the data sources are getting bound, and the Appian home page is showing up!! However, when I try to login using the default username and password, the page just refreshes and showing login page again.

Another issue is I am seeing both suite.ear and appian-mysql-ds.xml under "Deployments" and I don't see any data sources in Datasources tab anymore. Any idea why? I have included the screen shots and also the server.log file.

server.log

If conf.suite.SCHEME in custom.properties is set to http, you need to remove the following lines from web.xml in <APPIAN_HOME>\\ear\\suite.ear\\web.war\\WEB-INF\\
          <cookie-config>
          <http-only>true</http-only>
          <secure>true</secure>
          </cookie-config>
          <tracking-mode>COOKIE</tracking-mode>

You can also refer the below link for the same.          
forum.appian.com/.../Post-Install_Configurations.html

Yep, once I removed these links, its up and running. I had removed it earlier but when I started using configure script it got overwritten. Thanks!