Patents Act, 1970
107. Defenses, etc in suits for infringement
(1) In any suit for infringement of a patent, every ground on
which it may be revoked under section 64 shall be available as a ground for
defense.
(2) In any suit for infringement of a patent by the making,
using or importation of any machine, apparatus or other article or by the using
of any process or by the importation, use or distribution of any medicine or
drug, it shall be a ground for defense that such making, using, importation or
distribution is in accordance with any one or more of the conditions specified
in section 47.