This is my personal experience with Mantri developers, I had booked a flat in Mantri Serenity Bangalore in 2013 and the project was to be ready by 2016, they claimed a delay of 1 year and said possession moved to 2017, now in 2017 they have moved the date to end of 2018. Totally ruthless and unethical and to top it all unresponsive too.
To add to my vows I booked with Pre-EMI scheme(Full payment while booking and builder pays interest amount till possession), now they claim the interest will not be paid for the delay caused by them and hardly the payment is made on time, there is always a delay in payment.
Now that I want to sell the flat, they are not even allowing me to do so till completion, they have completely framed customers.
Humble request not to trust Mantri Developers, please do not buy properties from them, they are the most untrustworthy builders in Bangalore today.