Disclaimer : This answer is purely an opinion based on some data and not meant offend anyone and not based on any scientific research or survey.

Many people generally believe that :

South Indians are more intelligent compared to other Indians

Middle India comes next,

Whereas North Indians come third.

When IT COMES TO KSHATRA TEJA, the PHYSICAL MIGHT, more NORTH INDIANS ARE IN MILIRARY.

But, TALKING OF FINANCE, MIDDLE INDIANS ARE RICHER!

BUT INTELLIGENCE IS DIFFERENT FROM WISDOM.

INTELLIGENCE IS MORE THEORETICAL IN NATURE RELATED TO STUDIES AND CREATIVITY, IMAGINATIVE THINKING WHICH CANNOT BE LEARNT MUCH.

WHEREAS

WISDOM IS THE PRACTICAL OR CRITICAL THINKING POWER WHICH CAN BE LEARNT BY MANY METHODS.

OFTEN PEOPLE WHO ARE NOT INTELLIGENT ARE WISE AND ARE WISE AND ARE ALSO PRACTICALLY SUCCESSFUL IN LIFE.

EVEN ILLITERATES/SCHOOL DROPOUTS CAN BE WISE AND SUCCESSFUL IF THEY UNDERSTAND WHOM TO TRUST.

Definitely every state has its own different percentage of intelligent, strong, and wise men and women. There can be no dispute about that as no two states or countries are equal.

You may differ as there could be many exceptions out there.

I would like you to wait till you read this article fully before you judge or jump to any conclusion.

Historically speaking, the three main philosophers of India, who wrote treatises explaining Vedas and Upanishads, Lord Madhwacharya, Shri Ramanujacharya, and Shri Shankaracharya - all hailed from South Indian states of Karnataka, Tamil Nadu and Kerala respectively.

Thus,

Karnataka

Kerala

Tamil Nadu

Andhra Pradesh (old)

Come under this division .

Most educational institutions of today are located in the South. Premier Science Centers such as IISc and ISRO are located in the South.

A sizeable portion of Indian Tech Guys and medical professionals residing abroad are from South India.

In South India, thugs cheat you so cleverly that you take money out of your pocket on your own and give them and also may fall at their feet. By the time you discover the cheating, it will be too late.

South India: Why are South Indians known to have such an amazing intellectual capability?

In the North, they loot you at Gunpoint or knifepoint. You can find plenty of examples of both type of incidents in newspapers.

Middle Indians are normally mediocre Intelligent (not always) but are very good at management. They are good businessmen and make lot of money. Look at Gujarat, Bengal and Maharashtra for example. Bengal might have not realised its wealth potential as a result of communist rule for decades.

Why are Gujaratis so good at business in India?

North Indians are generally physically very strong and brave which you can undoubtedly witness and agree (as compared with Southerners). You find more people from North in Military Service.

Read the following article in Quora which proves that point.

Why-are-there-more-soldiers-from-north-India-in-Indian-army

Indian business is mainly controlled by Gujaratis and Maharashtrians.

Another interesting factor to note here is how one's language affects one's behavior or nature.

South Indians languages have lot of recurring sound of short “a" vowel sound (as in “un") usually in words spoken or written. For example : “Rama" as against “Ram” without the “a" sound at the end.

Short vowel “a" is known as the mantra of Lord Brahma the creator and whoever pronounces that more are blessed by Saraswati and become intelligent and knowledgeable like South Indians.

The vowel sound “u" is used more in middle Indian languages such as Marathi. “u" sound is the mantra of Lord Vishnu the maintainer/ manager of the universe. Whoever uses more of the sound of “u" as in “good”, is blessed by Goddess Lakshmi and turn wealthy, good managers and businessmen, earning a lot of money.

The sound of “m" (pronounced as the last letter in “mum”) is used much more in Northern languages. The sound of “m” is the mantra of Lord Shiva and whoever uses that more is blessed by Kaali (wife of Shiva) and thus grow physically strong.

Science may ascribe this distribution of qualities totally to genes. As per scriptures, people of like qualities are born in the neighbourhood of similar personalities.

Apart from all this, the food habits of different regions also have an effect on the people's personalities.

Just as an Atom bomb explodes when two separated pieces of fissile material unite, whole of India shall explode into a Superpower when the North, Middle and South Indians unitedly co-exist cooperating with each other in terms of knowledge, business and physical might

When Jnana (spiritual knowledge) of saints from South, Bhakti or devotion of Devotees from Middle India and Vairagya or renunciation of Yogis from North unite (one is liberated as a Yogi chants “AUM" -pronounced as long Ohm-, the three energies -Saraswati-Lakshmi-Parvati or Kaali being knowledge, money and physical might-of all three Trinities -Brahma -Vishnu -Maheshwara, who create, maintain and destroy) unitedly bless the person perfecting and liberating him or her thereby.

Below link gives similar opinions :

Which state's people in India are considered the most intelligent?

What is the IQ distribution across different Indian states?

JUST AN OPION BASED ON SOME OBSERVATIONS!