As you have asked about the state and post preference order in SSC CGL exam, I am giving you information about it, check below for the details

You cannot select the state as it will be allotted to you but you can give the preference for the posts in SSC CGL

You can fill the posts in given order

Assistant Audit Officer
Inspector (Examiner) (CBEC)
Income Tax Inspector (CBDT)
Assistant (MEA)
Inspector (Central Excise) (CBEC)
Inspector (Preventive Officer) (CBEC)
Assistant Enforcement Officer (AEO)
Assistant (Central Vigilance Commission)
Assistant (AFHQ)
Assistant (Ministry of Railway)
Assistant (Intelligence Bureau)
Assistant Section Officer (CSS)
Sub Inspectors (CBI)
Assistant (Other Ministries)
Divisional Accountant (CAG)
Inspector (Narcotics)
Assistant (Other Ministries)
Sub Inspectors (NIA)
Statistical Investigator
Inspector (Dept. of Post)
Sub-Inspector (Central Bureau of Narcotics)
Auditor (C&AG, CGDA, CGA)
Tax Assistant (CBEC & CBDT)
Accountant/ Junior Accountant (Offices under C&AG, CGA & others)
Senior Secretariat Assistant
Compiler (Registrar General of India)