The funds will be used mainly for business expansion and support working capital requirements.
The mop-up follows Rs four lakh crore raised by Indian companies through debt in last financial year, 2014-15.
According to the Securities and Exchange Board of India data, companies garnered Rs 20,692 crore in May after raising Rs 84,807 crore in April, taking the total amount to Rs 1,05,499 crore.
April marked the highest-ever fund-raising by Indian companies in a single month since January 2007. Data prior to this period is not available on Sebi Web site.
"After a spectacular past fiscal, we are upbeat about overall fund raising through the private placement of corporate bonds route for the current financial year (2015-16) as well," an industry expert said.
In debt private placements, firms issue debt securities or bonds to institutional investors to raise capital.
In terms of numbers, 629 issues were floated during the first two months of the financial year 2015-16.