Hi Sravanthi,

Please find the steps to Enable:


Submit a case to Salesforce Customer Support with your request and include the following information:

Important: You must be an active System Administrator authorized on behalf of this Organization to request this feature. Activation of this feature can take up to 3 business days.

1. What is the Organization ID of the production or sandbox instance (please specify if sandbox or production) where you need the feature to be activated? (Navigate to Setup | Company Profile | Company Information):

2. Include the username you're using for this Organization.
Partners: If you're a Partner logging this case on behalf of a customer, please also grant login access for 3 days as a proof of authorization (support will use this to validate your request).

3. Confirm that you understand that once Multi-Currency is activated, it cannot be deactivated (we recommend testing this first in a trial, dev, or sandbox organization).

4. Confirm the date and time (including timezone) when you'd like Multi-Currency activation to take place.

5. Confirm that you consent to the lockout of this organization for a certain period of time as described below (please note that the time estimations listed are only indicative).

6. Confirm that you understand that activating the Multi-Currency feature will stamp all existing records with one currency code which will be the organization's default currency (this default can be altered after the process is completed, but will only affect existing records if done so through record updates).

Setting your Organization's default currency: Navigate to Setup | Company Profile | Company Information | Edit | Currency Locale. You can review the supported currencies and ISO codes in the article "Supported currencies," and confirm the ISO code you select.

7. Confirm that you've allowed support to activate Multi-Currency (You can confirm by navigating to Setup | Administration Setup | Company Profile | Company Information. Select “Allow Support to Activate Multiple Currencies,” then click Save). 

Activation considerations:

CAUTION: This process locks the org and prevents users from logging in and prevents any integrations from processing.
For small orgs, we can activate anytime as the org lock time will be typically less than 20 minutes.
 
For medium sized orgs, we can activate after 5 pm your time zone and the org lock time can be typically up to an hour. We will coordinate with you before proceeding.
 
For large orgs, we can activate after Friday 5 pm your time zone and the org lock time can be up to several hours. We must schedule these activations before the end of day Wednesday before the weekend of activation. We will coordinate with you before proceeding.

We cannot guarantee that any particular activation timeframe will be available, especially on short notice. We will do our best to accommodate the time requested, but be aware that the activation process may be initiated up to 90 minutes after the scheduled time.

To ensure a smooth transition to multiple currencies, some activations for larger organizations may need to be scheduled a week or more ahead of time to avoid release windows and maintenance.
Customer Support will work with you to schedule the activation for a time that works for your business needs while also avoiding any risks.
 
Additional activation considerations:
 
Once enabled, Opportunity records will have a new standard required picklist field called "Opportunity Currency" visible only in the "New" and "Edit" modes. The selected currency for each Opportunity is used for the primary amount field.
 
Reports will show primary amounts per the Opportunity currency for each included record. Reports will show converted amounts in the currency of the user running the report OR the currency set using the picklist in the bottom of the report criteria page.

Hope this helps.

Thanks,
Nagendra