I came accross below link that shows a table, indicating that Visualize.js is not free, is there any other way to confirm this ?
It is not free. Visual.js is a commercial product.
"It comes bundled with the commercial editions of TIBCO JasperReports® Server, specifically Jaspersoft AWS, Enterprise or Professional. Visualize.js currently does not support JasperReports Server Community Edition or the TIBCO JasperReports® Library. "