Definitely, this is not true. Though IIT-Palakkad is doing good and showing decent growth, it can't be ahead of the old and well-established IITs. Here are the best IITs in terms of different factors.

Academics & Research - IIT Hyderabad: 

IIT Hyderabad has tie-ups with Japanese universities and companies. The fractal academic system, innovative curriculum, great faculty, and locational advantage of the institute results in a good placement. It is undoubtedly one of the best IITs.

Alumni Network - IIT BHU:

BHU had a reputation of its own even before it was an IIT. It has a huge alumni network. You will get to meet IIT BHU alumni in top MNCs across the world. 

Coding Culture - IIT Patna & IIT Indore: 

IIT Patna and IIT Indore have been doing exceptionally well in competitive coding lately. Their performance in programming competitions, GSoC, and other similar events proves that. 

Although IIT Palakkad is a decent IIT, it still has a long way to go, before it can be considered as one of the best.