The HSN (Harmonised System of Nomenclature) code for tomato sauce is 2103. This heading includes sauces and preparations thereof; mixed spices and mixed condiments; mustard flour and meals and prepared mustards.
Here is a description:
21: Miscellaneous food preparations
03: Sauces and preparations thereof; mixed spices and mixed condiments; mustard flour and meals and prepared mustards
Specifically, tomato sauce can be classified under:
2103.20: Tomato ketchup and other tomato sauces.
For GST purposes in India, the GST rate for goods classified under HSN code 2103.20 is generally 12%.