Currently I have my salesforce org and Markting cloud integrated using Marketing Cloud Connect.Is there a way if I update any contact information (ex:Subscribtion details) in Marketing Cloud , I can update the same in salesforce.
Currently the synchronization via the connector only works unidirectional. As far as I know the only way to update data in the sales/service cloud is using the Sales & Service Cloud Activities or a Custom Activity that accesses the salesforce api in a Journey.
Additionally you can update a Salesforce Object via AMPScript: http://help.marketingcloud.com/en/documentation/ampscript/ampscript_syntax_guide/ampscript_functions_for_use_with_salesforcecom/updatesinglesalesforceobject52/
A third option for updating data in Sales/Service Cloud is by mapping profile attributes to fields on the Lead or Contact Object.
There are two options:
%%[ var @id set @id=CreateSalesforceObject('lead', 2, 'FirstName', 'Chris', 'LastName', 'Cruz') ]%%