Hi @Avik Mukherjee,
SSIS XML Configuration option is kept for backward compatibility with the obsolete SSIS 2005-2008R2 versions.
Starting from SSIS 2012 onwards, it is using Integration Services Catalog and SSISDB database. As end result, there is no need anymore to use XML file configuration.
Modern SSIS is using project level Parameters and Connections for Configuration. If needed, you could also use SSIS Environments.