update DeploymentGuide with new params and RG reuse steps

Author: Prasanjeet-Microsoft

docs/DeploymentGuide.md

@@ -90,25 +90,61 @@ powershell.exe -ExecutionPolicy Bypass -File ".\resourcedeployment.ps1"
 ```
 
 You will be prompted for the following parameters with this Screen :  
-<img src="./images/deployment/Deployment_Screen01.png" width="900" alt-text="Input Parameters">  
+<img src="./images/deployment/Deployment_Screen01.png" width="900" alt-text="Input Parameters">
 
-1. **Subscription ID** - copy/paste from Azure portal
-1. **Location** - Azure data center where resources will be deployed.
+1. **Tenant ID** - The Azure Active Directory (AAD) tenant ID. This is used for authenticating against Azure resources. Copy this from the Azure portal.
+Example: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
 
-    *Please [check Azure resource availability and note hardcoded regions](#regional-availability). The following locations are currently supported: 
+2. **Subscription ID** - The Azure subscription ID where resources will be deployed.
+Copy this from the Azure portal.
+
+3. **Environment Name** - A unique environment name (e.g., dev, test, prod).
+This is used to scope resource names and group deployments logically.
+
+4. **Resource Group Name** - The Azure resource group to deploy resources into.
+You may either:
+
+   - Specify an existing resource group to reuse it, [see below](#configuring-a-new-or-existing-resource-group) for more details, or
+   - Leave blank to auto-generate a new name.
+
+5. **Location** - Azure data center where resources will be deployed.
+
+    * Please [check Azure resource availability and note hardcoded regions](#regional-availability). The following locations are currently supported: 
 
     ```
     'EastUS', 'EastUS2', 'WestUS', 'WestUS2', 'WestUS3', 'CentralUS', 'NorthCentralUS', 'SouthCentralUS','WestEurope', 'NorthEurope', 'SoutheastAsia', 'EastAsia', 'JapanEast', 'JapanWest', 'AustraliaEast', 'AustraliaSoutheast', 'CentralIndia', 'SouthIndia', 'CanadaCentral','CanadaEast', 'UKSouth', 'UKWest', 'FranceCentral', 'FranceSouth', 'KoreaCentral','KoreaSouth', 'GermanyWestCentral', 'GermanyNorth', 'NorwayWest', 'NorwayEast', 'SwitzerlandNorth', 'SwitzerlandWest', 'UAENorth', 'UAECentral', 'SouthAfricaNorth','SouthAfricaWest', 'BrazilSouth','BrazilSoutheast', 'QatarCentral', 'ChinaNorth', 'ChinaEast', 'ChinaNorth2', 'ChinaEast2'
     ```
-1. **ModelLocation** - Azure data center where GPT model will be deployed.  
+6. **ModelLocation** - Azure data center where GPT model will be deployed.  
     The following locations are currently available :
     ```
     'WestUS3', 'EastUS', 'EastUS2', 'SwedenCentral'
     ```
 
-1. **Email** - used for issuing certificates in Kubernetes clusters from the [Let's Encrypt](https://letsencrypt.org/) service. Email address should be valid.  
+7. **Email** - used for issuing certificates in Kubernetes clusters from the [Let's Encrypt](https://letsencrypt.org/) service. Email address should be valid.  
+
+8. **GO !** - Deployment Script executes Azure deployment, Azure Infrastructure configuration, Application code compile and publish into Kubernetes Cluster.
+
+## Configuring a New or Existing Resource Group
+
+➕ Creating a New Resource Group
+
+You have two options:
+
+- Manually specify a resource group name (e.g., rg-myproject-dev)
+
+- Leave the input field blank — a new name will be auto-generated by the script
+
+🔁 Using an Existing Resource Group
+
+If reusing an existing Azure Resource Group:
+
+- Provide the exact name of the existing resource group
+
+- Ensure the environment name matches the original environment used for that resource group
+
+  ⚠️ After deployment, please restart the AKS (Kubernetes) service to ensure updated configurations are applied when using a reused resource group.
+
 
-1. **GO !** - Deployment Script executes Azure deployment, Azure Infrastructure configuration, Application code compile and publish into Kubernetes Cluster.
 
 <!-- 1. **Data File Upload and Processing**  - Once the deployment finished, The Sample Data File upload and Document processing starts. -->