Mantra Prayog is a concise Hindi spiritual guide that explores the practical application of selected mantras along with their correct जाप विधि (chanting methods) and सिद्धि विधान (attainment procedures) for seekers and practitioners. The book presents authentic traditional mantra practices, emphasizing disciplined repetition and the spiritual principles behind sound empowerment. It is tailored for those interested in mantra-based meditation, healing, and inner transformation through devotional discipline. Published by Randhir Prakashan, Haridwar, this 127-page paperback offers accessible explanations for both beginners and experienced sadhaks. The text serves as a compact reference for mantra chanting routines and their supposed energetic benefits rooted in Hindu mantra science.