Your job would mainly be to call customers who have not paid their EMI/loan payments on time and ask them to make the payment.
You would likely:
Make outgoing calls to customers.
Explain their overdue EMI/payment.
Ask when they can pay.
Discuss possible repayment arrangements.
Update payment/customer information in their system.
Maintain records/reports.
Deal with customers who may be angry or difficult.
Work toward monthly collection targets.
So this is not a straightforward data-entry/back-office job. It is a target-based calling/collection job.
? Salary
Since you're a fresher, their message says:
₹18,000 CTC
That means the advertised package is ₹18,000, but don't assume you'll receive exactly ₹18,000 in your bank account. Ask them whether ₹18,000 is gross salary or CTC, and what the in-hand salary after PF/ESI/other deductions will be.
Their experience structure is:
Experience Advertised CTC
Fresher ₹18,000
2+ years any field ₹18,000
1+ year Tele Collections ₹19,000
2+ years Tele Collections ₹21,000
Since you're a fresher, your category is ₹18,000.
? Incentives
They are saying you can earn additional incentives depending on your collection performance:
1st slab → ₹3,500
2nd slab → ₹5,000
3rd slab → ₹7,500
Additional spot incentive → ₹2,000/month, but only as a voucher
The important thing is that they haven't told you how much collection you need to achieve for each slab.
For example, they haven't explained whether you need to collect ₹X to get ₹3,500, ₹Y to get ₹5,000, etc.
So ask them for the exact incentive targets/slabs before accepting.