Service tax audit by st dept to builder

Dear Professional and friends, Recently ST dept issued a notice of intimation for conducting audit of service tax to builders under provision of service tax rule 1994 and read with section 174 (2) (e) of CGST act 2017.They have askd for docuemnts for service tax audit . My query is that can they call for list of documents and records for audit for the relevant audit period . They have not mentioned the periods for the audit. They have written that last audit done on 30.06.2017.But as pe rthe infomation from asseessee is that they have got first time this intimation. wil you guide me how to respondence to this notice of service tax audit of builder?