Regarding credit note in gst

Dear Team Members,

I have some issue regarding Credit note in GST..

Actually a party raise a bill in August month of Rs. 236000/- Including GST (GST amt : 36000/-) but we have not taken yet the ITC of this bill... After that party sent a Credit note in January month of Rs. 118000/- including GST (GST amt : 18000/-)... All details has been uploaded by them in GSTR1 in GST portal.

But i want to know can we take the ITC of this bill & how much amount 18000/- or 36000/-....

Want to know the process of claiming ITC...

Please rply asap.