Yes, it is available online.

Dr. K. R. Chandra’s Ph.D. thesis “A Critical Study of Paumacariyam” (Research Institute of Prakrit, Jainology & Ahimsa, Vaishali, 1970) has been digitised and can be accessed in full:

• As a complete PDF through the Shodhganga (Indian theses) repository.
• In an OCR + PDF format under the title “Paumacariya (critical study)” by K. R. Chandra on the WisdomLib site.

To locate it, search on the web for:

> A Critical Study of Paumacariyam K. R. Chandra PDF or > “Paumacariya (critical study)” K. R. Chandra Shodhganga

and you should reach the downloadable version.