Do you have to perform a monologue in year 11 for drama GCSE?

There's no single, universal requirement for a GCSE Drama exam. The specifics depend entirely on the exam board (e.g., AQA, Edexcel, OCR) and the particular specification they're using. Some exam boards might include a monologue as part of the assessment, while others might not. You need to check the specification document for your specific GCSE Drama course to find out what's required.