Join and Loft not working in Grasshopper

Hi @Aroma_Imran
Welcome to the group. It could well something fairly simple, but in order for one of the Grasshopper proficient users to help you, we need more than just a couple of screen grabs, as they really don’t say much in terms of data flow. Read this clear description of how to ask effective questions and make it easier for others to help you.
HTH, Jakob