Hi @leelakrishna.k,
Looking at the information and screenshot you have posted, it seems that your project expects HDFql.dll to be a typical .NET assembly file. Although both may have the same extension, i.e. dll, they are different as HDFql.dll (shipped in HDFql distribution package) is a native dynamic link (i.e. shared) library. Therefore, your project must deal with it as such. Please check this Stack Overflow post to get additional information about this subject and how to setup a .NET project to use a native dynamic link library.
Hope it helps!