Rule 86B under CGST Act - Goods and Services Tax - GST

One of my client has set off output tax with 100% ITC department issued notice to pay 1% cash.As per the frequent questions any month limit Rs.50 lakhs is not crossed but the turnover is more than Rs.6 crores in a financial year Rule 86B does not need to be complied with.If the turnover is less than Rs.6 crores in a financial year but the taxable supplies for any month exceeds Rs. 5o lakhs the Rule 86B stands attracted. I request the experts please clarify the issue how to proceed in the matter regarding if cash payment is made 1% how to get ITC