Delhi firm importing via chennai & selling to karnataka

Better to go for Highseas Sale.

1.In such case what taxes will be applicable other than customs duty and which jurisdiction applicable.

Answer: Other than Customs duties, you need to pay the applicable VAT/CST.  You can get exemption of Special Additional duty ( SAD) on imports, provided  you declare the MRP &the goods are indented for retail sale. Or Alternativley apply for refund and get SAD refund

2.What will be the best alternative for low tax incidence.

Answer : You can avoid VAT/CST provided the goods are sold on High Sea Sales,  In such case your buyer has to customs clear the goods from customs.

Yes, in This Case, Buyer Will Get to Know Your Purchased Price.

Since He is Paying Custom Duty

in case of HSS, buyer must have IEC otherwise will not able to file BOE.