Where the NET Frameworks directory located in System?

The default framework installations for Microsoft Dotnet of all versions will be installed in the below folders

C:\Windows\Microsoft.NET\Framework
And
C:\Windows\Microsoft.NET\Framework (Framework64)
eg:
v1.0.3705
v1.1.4322
v2.0.50727
v3.0
v3.5
v4.0.30319 (for V4.0 and V4.5 same folder but build version different)

Note for the Versions of 4.0 and 4.5 we will see only one folder that is "v4.0.30319" as the Microsoft Dotnet framework versions 4, version 4.5 has the same files but only difference is that the file build version will be different.
for Microsoft Dotnet Framework version 4.5 will have the build version greater than 17000.