You can register at IOIPrihatin website to get detail info from their agents. They will contact you promptly to explain the details (kudos for their service).
The info I got is from last month so not sure any change to their package this month.
I think 32 months free installments are equal to about 11-12% rebate. You need to sign the SPA within 7 days after booking even if loan is not yet approved.
You cannot sell the house for 10 years. if your loan approved is less than the rebate, then you need to topup to fill the gap.

Also, different project may have different package.

Does anyone know is it easy to get 90% loan for 16 Sierra? I keep hearing from people or news that getting house loan is difficult these days...