Hello Priya,
slab rates you given for Tamilnadu are correct. i given for Coimbatore region.
Tax deduction is takes place 2 times that is April to September and Oct to March.
for tax deduction month they given optional month's like August / September & Jan / Feb if any difference due to salary hike adjustments will happen in March month. This is SAP standard.
Best Regards,
Praneeth kumar