However, before I give you the review, I must address the "20th Edition" aspect. The most common versions found in libraries and classrooms are the Revised Editions published by S. Chand, often updated by his colleague J.K. Gupta. It is highly likely you are looking for the latest available edition (often labeled simply as "Revised Edition" or around the 10th-12th impression in some contexts).
While there is no official "20th edition" solution manual specifically titled for " Fluid Mechanics R.S. Khurmi , the primary textbook used is Hydraulics, Fluid Mechanics and Hydraulic Machines fluid mechanics 20th edition rs khurmi solution manual pdf