Exception while loading assemblies: System.IO.FileNotFoundException: Could not load assembly 'Microsoft.Practices.Unity, Version=4.0.0.0, Culture=neutral, PublicKeyToken=6d32ff45e0ccc69f'. Perhaps it doesn't exist in the Mono for Android profile? File name: 'Microsoft.Practices.Unity.dll' at Java.Interop.Tools.Cecil.DirectoryAssemblyResolver.Resolve (Mono.Cecil.AssemblyNameReference reference, Mono.Cecil.ReaderParameters parameters)
Can you please suggest for solutions
Your error message tells you everything you need to know: Microsoft.Practices.Unity, Version=4.0.0.0. You have a reference to v4.0 of Unity. Prism 7 references v5.0. You need to check your dependencies as somewhere you have a reference to the old package.
Also note that due to some changes that were made in the way that Unity ships, Prism has also made a change from referencing the Unity package to the Unity.Container package as of Prism 7.1.