Hi Vijay,

Here you go!

- override the default_get method to achieve this.

 in dictionary you have to pass key as your field name for which you want to set default value, would your updated value for that field.

#v7
def default_get(self, cr, uid, ids, context=None):        
    # Either prepare your dictionary here to update in result dictionary    
    result = super(class_name, self).default_get(cr, uid, ids, context=context)       # or directly update your result dictionary with new fields value to be updatr    return result

#v8
@api.model
def default_get(self, vals):    
    #update dictionary with default fields 
    result = super(product_new_revision, self).default_get(vals)
    #Update dictionary with default fields 
    return result

eg. Update dictionary value in this format -> {'field_name': 'default value'}

Hope this will help.

Regards,

Anil.