This actually covers a lot of ground, from ancient and medieval issues through those of the British colonial period and then into the coinage of the modern independent nation.
I'll start this off with a common enough example (between Bombay and Lahore, nearly 119 million produced). It is struck in .500 fine silver. This is the version from later in the year that has a security edge (KM# 547) as opposed to the earliest simple reeded edge type (KM# 546).
Also, here're a couple of websites on this topic worth perusing:
I'll start with a tough one. This is a 35 m.m. silver Madras Half Pagoda(1808-11). These were struck on blanks made from Spanish Colonial 8 reales. Portions of the under coin can be seen in this example.