Hi Ramesh,
I'm not sure which schematic you are referring to, but the MSC1210EVM schematic that I drew did not have AVDD, REFOUT and REFIN+ connected together. You should not connect the 5V supply and the 2.5V reference output together. If you are using the reference at 2.5V, you should disconnect AVDD from the REFOUT and REFIN+ pins.
The INA826 has the REF pin floating. This means that there is no common mode established for the part. This also means that the output of the INA could float anywhere with the range of the supply. This also means that the Absolute Maximum Ratings can be violated if the output floats above AVDD. You should either tie the REF pin of the INA to either GND or at mid-AVDD supply to set the common mode of the INA. You must also add protection so that it is not possible for Absolute Maximums to be exceeeded. One way to add protection is to change the value of the resistors R15 and R17 to at least 1.4k ohms.
I would also suggest that you change the RC that is on the RESET pin of the MSC1210 to a supply supervisor. This will ensure that the MSC1210 is held in RESET for a sufficient amount of time on power up and will also hold the device in RESET if a brownout should occur.
Best regards,
Bob B