Hi Vishal,
this Text is not directly accessible for an Form Adaption.
But with the PDI this field text can be added as an text for an new or existing field (e.g. the customer Information Bock) in the quote.
The Path to the content of this Text is Material->TextCollection->Text(TypeCode:10006, Detail Description)->TextContent->Text.content.
Best regards
Tobias Kuhn