No, there is no word limit in IELTS speaking test but you have to speak at least 2 minutes to achieve good band scores.
Answer is , theres no limit for spoken words. Candidate has to organise reply of the question in a way that it covers the adequate vocabulary, relates with the answer and addresses the question in relevant manner.In this course, answers should not sound like a story.
It is expected to speak atleast (refer below) in each round,
Introductory round - 1-3 sentences
Cue card round - 15-20 sentences
Follow up round - 5-8 sentences
Trainers would easily recognize your memorised words or answers so try to keep it simple and look confident.
Happy speaking guyz ?!!