How Can i Update only one Column of SQL Table via store procedure with passing rest column value null
You can do a COALESCE between the passed in parameters and the existing values.

When the passed in value is NULL, the query will retain the existing values.

This will, however, make it difficult to update to NULL if you do actually require the Nulling of these values.

CREATE PROCEDURE [dbo].[spUpdateUser]
@ID int,
@UserID varchar(50) = null,
@Name varchar(50) = null,
@FatherName varchar(50) = null,
@DOB date = null
AS
BEGIN
update tblUser set
    UserID = COALESCE(@UserID, UserID),
    Name = COALESCE(@Name, Name),
    FatherName = COALESCE(@FatherName, FatherName),
    DOB = COALESCE(@DOB, DOB)
    where ID = @ID
END