A higher basic salary increases your EPF contribution (building retirement savings) and your HRA calculation (if you pay rent and use the old regime), but it also slightly reduces your immediate take-home pay since more goes into mandatory deductions. A lower basic with a higher "special allowance" component does the opposite — more take-home now, less forced saving.
It's also worth asking about the variable pay structure — what percentage of your CTC is fixed versus performance-linked, and what the realistic historical payout has been, since a large variable component that rarely pays out in full effectively inflates the headline number without matching reality.
Beyond pure compensation, benefits like additional NPS contribution matching (deductible even under the new regime), health insurance coverage for parents, and meal or fuel allowances (though these lost most of their tax advantage under recent changes) are all worth clarifying, since they affect your real financial position beyond what a single CTC figure conveys.