Connect Dynamics CRM/365 V9 with Asp.net Application c#

 using System.ServiceModel.Description;
 using Microsoft.Xrm.Sdk;

IOrganizationService organizationService = null;
        public void Connection()
        {
            try
            {
                ClientCredentials clientCredentials = new ClientCredentials();
                clientCredentials.UserName.UserName = "username";
                clientCredentials.UserName.Password = "password";

                // For Dynamics 365 Customer Engagement V9.X, set Security Protocol as TLS12
                ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12;
                // Get the URL from CRM, Navigate to Settings -> Customizations -> Developer Resources
                // Copy and Paste Organization Service Endpoint Address URL
                organizationService = (IOrganizationService)new OrganizationServiceProxy(new Uri("https://orgname.api.crm4.dynamics.com/XRMServices/2011/Organization.svc"),
                 null, clientCredentials, null);

                if (organizationService != null)
                {
                    Guid userid = ((WhoAmIResponse)organizationService.Execute(new WhoAmIRequest())).UserId;

                    if (userid != Guid.Empty)
                    {
                        Label1.Text = "Established Connection!!!";
                    }
                }
                else
                {
                   Label1.Text = "Failed to Established Connection!!!";
                }
            }
            catch (Exception ex)
            {
                Label1.Text = "Exception caught - " + ex.Message;
            }
        }

Plugin Registration Tool For Dynamics 365 V9

Step 1: Create a folder in D Drive and name it as “Dynamics_365_Development_Tools“
Step 2: Click on Windows, search for Windows PowerShell and open it.
Step 3: Type the below command to change the directory.

cd D:\Dynamics_365_Development_Tools

and press Enter.
Step 4: Copy & Paste the below PowerShell script in PowerShell Window to download tools from Nuget.

$sourceNugetExe = "https://dist.nuget.org/win-x86-commandline/latest/nuget.exe"
$targetNugetExe = ".\nuget.exe"
Remove-Item .\Tools -Force -Recurse -ErrorAction Ignore
Invoke-WebRequest $sourceNugetExe -OutFile $targetNugetExe
Set-Alias nuget $targetNugetExe -Scope Global -Verbose

##
##Download Plugin Registration Tool
##
./nuget install Microsoft.CrmSdk.XrmTooling.PluginRegistrationTool -O .\Tools
md .\Tools\PluginRegistration
$prtFolder = Get-ChildItem ./Tools | Where-Object {$_.Name -match 'Microsoft.CrmSdk.XrmTooling.PluginRegistrationTool.'}
move .\Tools\$prtFolder\tools\*.* .\Tools\PluginRegistration
Remove-Item .\Tools\$prtFolder -Force -Recurse

##
##Download CoreTools
##
./nuget install Microsoft.CrmSdk.CoreTools -O .\Tools
md .\Tools\CoreTools
$coreToolsFolder = Get-ChildItem ./Tools | Where-Object {$_.Name -match 'Microsoft.CrmSdk.CoreTools.'}
move .\Tools\$coreToolsFolder\content\bin\coretools\*.* .\Tools\CoreTools
Remove-Item .\Tools\$coreToolsFolder -Force -Recurse

##
##Download Configuration Migration
##
./nuget install Microsoft.CrmSdk.XrmTooling.ConfigurationMigration.Wpf -O .\Tools
md .\Tools\ConfigurationMigration
$configMigFolder = Get-ChildItem ./Tools | Where-Object {$_.Name -match 'Microsoft.CrmSdk.XrmTooling.ConfigurationMigration.Wpf.'}
move .\Tools\$configMigFolder\tools\*.* .\Tools\ConfigurationMigration
Remove-Item .\Tools\$configMigFolder -Force -Recurse

##
##Download Package Deployer 
##
./nuget install Microsoft.CrmSdk.XrmTooling.PackageDeployment.WPF -O .\Tools
md .\Tools\PackageDeployment
$pdFolder = Get-ChildItem ./Tools | Where-Object {$_.Name -match 'Microsoft.CrmSdk.XrmTooling.PackageDeployment.Wpf.'}
move .\Tools\$pdFolder\tools\*.* .\Tools\PackageDeployment
Remove-Item .\Tools\$pdFolder -Force -Recurse

##
##Remove NuGet.exe
##
Remove-Item nuget.exe

Press Enter.
Step 5: Below Tools will be downloaded to D:\Dynamics_365_Development_Tools\Tools Folder.

Source Link: https://arunpotti.wordpress.com/tag/plugin-registration-tool-dynamics-365/