Yes. You can change the currency of the records in Zoho CRM. But this is subject to certain conditions.
If you have NOT enabled Multi-currency:
You can change the default currency by changing the Locale Information under Setup > General >Company Details > Locale Information > Manage Multiple Currencies. Select the currency that you want. The currency you set will apply to all records across CRM.
If you have enabled Multi-currency:
You can also change the currency for an individual record by editing it.
Go to a module and select a record.
In the Record's Details page, click Edit.
Select the desired currency from the Currency picklist field.
Click Save. The currency is now updated only for this record.
Note: You cannot mass update currency for a group of records.