Hi Chi - here are some answers for you:
1. When do we plan to support SQL Server 2016 as the Jasper database?
Answer: Currently both Jasper 6.3 and 6.4 are not certified with Sql 2016. You can see that here: System Requirements - CA Business Intelligence JasperReports® Server - 6.3.0 - CA Technologies Documentation
This would be on Tibco to certify Jasper against that version of SQL so we cannot answer as to when that will happen. You can maybe try asking that on the Tibco Jasper community at http://community.jaspersoft.com
2. Can current 6.3 version connect to SQL Server 2016 as a datasource?
Answer: Yes, Jasper can report against a SQL 2016 database. You can see here in the 17.1 docs that Insights Datamart (which Jasper reports against for Xflow Insights) is compatible with SQL 2016 Enterprise: Supportability Matrix - CA Service Management - 17.1 - CA Technologies Documentation
3. When will the product support installing on Windows Server 2016?
Answer: Again this would be a question for the Tibco community.
4. When will the product support Tomcat 9 (as 8.0 is End of Life)?
Answer: Again same here - this would be something you would need to ask Tibco.
I would recommend that you either open a case with Tibco following our internal process (ping me offline if you need help with that), or register on the TIbco community and ask the questions there. Unfortuantely as Jasper is not a CA product, we cannot certify it with platforms.
Hope this helps,
Jon I.