There cannot be parallel proceedings.
The officer who started first should finish the assessment.
You can ask the other department to drop th proceedings.
https://www.taxmanagementindia.com/visitor/detail_article.asp?ArticleID=12411
4. Parallel proceedings by Central and State Authorities unacceptable
Shree Cement Ltd Vs Union of India (Rajasthan High Court) [W.P.No.17725 of 2023]
Facts of the Case:
Parallel show cause notices were issued by Central and State GST Authorities on the same subject matter.
Contention of the Petitioner:
· It was claimed that the action of the officials of the CGST/SGST of issuing simultaneous show cause notices on the same subject matter is contrary to Section 6(2)(b) of the CGST/SGST.
· It is also submitted that in terms of the guidelines issued by the GST Council dated 20-9-2017, the Central Government and State Government have decided to assign the taxpayers registered in the State of Rajasthan to one Authority and as per the same, the Administrative Authority in the case of petitioner is the Central Government. However, in violation of the guidelines, the officials of the State GST Council have also issued a show cause notice to the petitioner.
Decision Held:
The High Court granted an interim stay against adjudicating aforesaid SCNs and issued notice to both, Central and State GST authorities to respond.