Need advise please on the Biometric appointment received for I539 (B2 Extension) after parents left


New Member
I applied B2 extension of stay I539 application in October 2020 to be extended until Jan 2021. My parents left to India in Jan 2021 and I received Biometric appointment in June 2021 for 2nd July 2021.

Need advise please ,
1. Can my parents do biometric in india ?
2. Should i send a withdrawal letter via certified mail for the submitted I539 application ? what documents should i attach ?
3. If i submit the withdrawal, will their stay between November 2020 and jan 2021 be considered out of status ?
4. Will the withdrawal create any issues during their reentry in the future ?