A processor implemented method comprising: extracting metadata associated with one or more source documents, wherein the one or more source documents are identified as having a structured form, a semi-structured form, an unstructured form, an image form or a combination thereof, based on the extracted metadata, and wherein the step of extracting data comprises using at least one of a deterministic approach and a probabilistic approach; processing the one or more source documents for extracting data comprising entities and attributes thereof; extracting data from the one or more source documents in either native language or English language based on cognitive processing of the one or more source documents to obtain an Enterprise-to Business (E2B) Extensible Markup Language form having a pre-defined set of templates; evaluating the Enterprise-to Business (E2B) XML form for accuracy and completion of the step of extracting data, wherein the step of evaluating the E2B XML form comprises: correlating the set of templates obtained from the E2B XML form to check similarity across the one or more source documents; and computing a confidence score of extraction of entities and attributes in each of the E2B XML form based on one or more of: the form of the one or more source document; the method of validating the one or more entities based on a context dictionary match or a probabilistic approach; and accuracy of the context dictionary match; and computing an overall confidence score for each of the E2B XML form based on the confidence score of each of the extraction of entities and attributes and pre-defined weightages thereof; and deciding validity of the one or more source documents based on existence of content in the pre-defined set of templates. extracting metadata associated with one or more source documents, wherein the one or more source documents are identified as having a structured form, a semi-structured form, an unstructured form, an image form or a combination thereof, based on the extracted metadata, and wherein the step of extracting data comprises using at least one of a deterministic approach and a probabilistic approach; processing the one or more source documents for extracting data comprising entities and attributes thereof; extracting data from the one or more source documents in either native language or English language based on cognitive processing of the one or more source documents to obtain an Enterprise-to Business (E2B) Extensible Markup Language form having a pre-defined set of templates; evaluating the Enterprise-to Business (E2B) XML form for accuracy and completion of the step of extracting data, wherein the step of evaluating the E2B XML form comprises: correlating the set of templates obtained from the E2B XML form to check similarity across the one or more source documents; and computing a confidence score of extraction of entities and attributes in each of the E2B XML form based on one or more of: the form of the one or more source document; the method of validating the one or more entities based on a context dictionary match or a probabilistic approach; and accuracy of the context dictionary match; and correlating the set of templates obtained from the E2B XML form to check similarity across the one or more source documents; and computing a confidence score of extraction of entities and attributes in each of the E2B XML form based on one or more of: the form of the one or more source document; the method of validating the one or more entities based on a context dictionary match or a probabilistic approach; and accuracy of the context dictionary match; and the form of the one or more source document; the method of validating the one or more entities based on a context dictionary match or a probabilistic approach; and accuracy of the context dictionary match; and computing an overall confidence score for each of the E2B XML form based on the confidence score of each of the extraction of entities and attributes and pre-defined weightages thereof; and deciding validity of the one or more source documents based on existence of content in the pre-defined set of templates.