Hello Ravindra, Nitin.
In continuation to below mail variation of 170Kgs is very minor in terms of percentage less 1%,
there is nothing in writing as such from Indian customs on such variation, but understanding is customs is considerate to accept minor weight variation.
Customer or his CHA should be able to convince customs for the same.
Also sharing with you the Nava Sheva Customs Standing order on such variations found for furniture’s and marble, hope this help’s customer explaining custom the issue on basis of this order.
http://www.jawaharcustoms.gov.in/newsite/StandingOrders/SO2010/SO-22-10.htm