Thank you so much Mana.You are really very helpful.I just missed one condition that the columns doesnt have same columns .
File A.xsl has Country salary gender value1 value2 Region1 City Price
File B.xsl has Country salary gender value1 value2 University School Grade

Master.xslm should have FileName Gender/Value1 Value 2 Region School Price Grade

Can you please tell me the code for selecting specific columns (as expected in result Master.xslm) and copy pasting accordingly.

I need to submit this today.I will be really greatful if you can help me with this.