Validating the GST Identification Number (GSTIN)

The following image describes the format of the GST Identification Number: - The first 2 digits denote the unique *State Code* in accordance with the Indian Census 2011. For instance, the *State Code* of New Delhi is '07' and that of Karnataka is '29'. - The next 10 characters denote the *PAN* (*Permanent Account Number*) of the taxpayer. - The 13th digit denotes the *Registration Number* (or *Entity Number*) of the tax payer with the same *PAN*. - The 14th digit is 'Z' by default for all – not intending anything currently. - The 15th digit is the *Check sum digit* – can be a number or an alphabetical character. Perhaps I can carry out the validation by means of a PATINDEX or a Regex?