Yes the private pilot license course duration can vary slightly from one institute to another. On average the ppl course duration in India ranges between 6 to 12 months. This includes both ground training and flying training.
Several factors affect the ppl duration such as:
Weather conditions that may delay flights
Availability of aircraft and instructors
Institute schedule and resources
Student's own learning pace and exam performance
Because of these reasons the private pilot license duration may be shorter in some institutes and longer in others.
While most institutes follow DGCA guidelines the actual ppl course duration depends on training speed and available facilities. Choosing a well equipped institute with good aircraft availability and experienced trainers can help you complete your private pilot license course duration smoothly and on time.