Can we update parent record with workflow field update?

Hi Pranav,
By following the below steps you can achieve how to update parent field using workflows.
Let us take Account and Opportunity objects as an example.

1. Create a workflow rule for Opportunity Object (Detail/Child object)
2. Set the evaluation criteria as required.
3. set the Rule Criteria as required.
4. Click next.
5. Select field update from the 'Add workflow action' dropdown menu
6. Fill in the Name, Unique Name & Description. If you notice 'Field to update' will appear as a dropdown with two possible values a) Opportunity b) Account (As account is a master object for Opportunity)
7. When you select Account object in the above dropdown, the second dropdown shows all the standard & custom fields from account object.
8. Select any field and set the formula to update that field.

This is how you can update the parent field from a workflow rule set on child object by setting the criteria on child object.

Thanks.