Hi priya welcome to sap s4hana finance you can not directly install SFIN add on by SAINT you require a solution manager system it will generate all the relevant components create .XML file by using SUM you can install sap simple finance 2.0 add on .you can find relevant documents on our sap community network .let me know if you require more guidance .
https://websmp102.sap-ag.de/~sapidp/012002523100012043322015E.pdf