If you need a resource for computational PDEs and cannot purchase the book, the following Open Educational Resources (OER) are excellent, legal, and free alternatives:
It is important to note that M.K. Jain is most famous for the book "Numerical Methods for Scientific and Engineering Computation" (co-authored with Iyengar and Jain). While the title you searched for is slightly different, this is likely the book you are looking for, as it contains extensive chapters on PDEs (Parabolic, Elliptic, and Hyperbolic equations). If you need a resource for computational PDEs
If you can't find the specific book you're looking for, there are many excellent textbooks on computational methods for partial differential equations by other authors. Some popular ones include: OpenStax & Wikibooks:
These might be available in your university library or online through legal channels. and free alternatives: