Syed Hajir Ali M,
One thing to note from your policy screen capture is that you need to set the context variable json in the Apply Transformation to section of the Apply XSL Transformation assertion. Below are some basic XSLT for conversion:
SOAP to XML
Use case: an XML over HTTP legacy endpoint expose as a soap service by the SSG. This xslt removes the incoming SOAP envelope and keeps only its contents.
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">
<xsl:template match="soap:Body">
<xsl:copy-of select="./*[1]" />
</xsl:template>
</xsl:stylesheet>
XML to SOAP
Use case: same as above, add the soap envelope to the returning answer.
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">
<xsl:template match="/">
<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">
<soap:Body>
<xsl:copy-of select="." />
</soap:Body>
</soap:Envelope>
</xsl:template>
</xsl:stylesheet>
Sincerely,
Stephen Hughes
Director, CA Support