Hi Pradeep,
Thank you for reaching out to us. If you’re reporting on the campaign level for 10 campaign reporting data (Campaign_Performance_Report for example, which queries the campaigns in your account), that will count as 1 API report download towards your (basic level) 1000 daily quota. However, if you’re reporting on data specific for one campaign and query that report for 10 campaigns, that will count as 10 API report downloads towards your quota. Let me know if you have further questions.
Thank you,
Bryan, Google Ads API Team