ITC claimed at once , Is it Okay & allowed ?

 Have a confusion about ITC claim  

 For April 2018- March 2019 (Previous financial year),   I had  30 k rupee ITC total  available (showing filed in GSTR 2A) . I claimed the entire  amount in Sept 2019 GSTR-3B , is it Okay ?   I mean I did not claim it in subsequent months but later on SEPT 2019 I claimed all at once.

any rule change for claiming ITC ?