had applied for my l1b individual extension at the california center towards end of August 2018. more than 6 months now and no update received. ...

correction to my above comment. rfe was recevied around 27 mar. filing done on 27 aug. took almost 7 months under normal mode. am still preparin...

Received RFE on 27th aug

which center did you apply to. since yours is outside normal processing time were you able to submit an enquiry to uscis and get a response

Which center was your petition filed at - california or texas

I have not tried so not sure. On the website it asks for the receipt number and date of filing to raise a request

which center had you applied, was it california