Is testing negative several times negative for hiv 1 and hiv 2 after 16 years of unprotected sex is to fear about. last such test done in june 2015.i ?

Tests very reliable: The standard tests for HIV, including those used in India (a medically sophisticated country) are 100% reliable if enough time has passed since the last possible exposure. Depending on exactly which tests you had, your last negative result proves you did not have HIV from any exposure up to 4-8 weeks earlier. It doesn't matter how high the risks for HIV were at the time; the test result rules!