GoI brought P8i, with out any test, matter of fact, its still under development stage, even USN give ioc after GoI choose P8.
from, en.wikipedia.org/wiki/Boeing_P-8_Poseidon-
''The P-8's first flight was on 25 April 2009'' & ''In January 2008, Boeing proposed the P-8I, a customized export variant of the P-8A, for the
Indian Navy.
[69] It features two major components not fitted on the P-8A, a Telephonics APS-143 OceanEye aft radar and a magnetic anomaly detector (MAD). On 4 January 2009, India's
Ministry of Defence signed a US$2.1 billion agreement with Boeing.'' & ''On 4 March 2012, the first production P-8A was delivered to the USN''
Its very hard to find a decade old articles & GoI brought p8 as a goodwill for removing sanctions.
My mistake, P8i also an experimental purchase like vikky. Only difference is, one with issues & other don't.