Step 1: Understanding the Concept:
GSTIN stands for Goods and Services Tax Identification Number. Every registered taxpayer gets one unique number.
Step 2: Structure of GSTIN.
GSTIN has 15 characters in total. They are built from these parts.
First 2 digits: State code.
Next 10 characters: PAN of the taxpayer.
13th character: Number of registrations in the same State on one PAN.
14th character: The letter Z by default.
15th character: A check code.
Total: 2 + 10 + 1 + 1 + 1 = 15.
Step 3: Why the other options are wrong.
10 is the length of a PAN, not a GSTIN. 13 and 14 are only partial counts of the GSTIN characters.
Final Answer:
GSTIN has 15 characters, which is option (A).