Where does Quran say about the two nation theory?

Answer 1

Quran does not say about a two nation theory. Quran says that God (Allah in Arabic) created people in different nations with different cultures, faiths, colors, and/or ideologies to compete together for mankind benefit and for God satisfaction and to live together kindly and peacefully.

quran says:

يَا أَيُّهَا النَّاسُ إِنَّا خَلَقْنَاكُم مِّن ذَكَرٍ وَأُنثَىٰ وَجَعَلْنَاكُمْ شُعُوبًا وَقَبَائِلَ لِتَعَارَفُوا ۚ إِنَّ أَكْرَمَكُمْ عِندَ اللَّـهِ أَتْقَاكُمْ ۚ إِنَّ اللَّـهَ عَلِيمٌ خَبِيرٌ ﴿١٣﴾

Meaning English translation:

{ O mankind, indeed We have created you from male and female and made you peoples and tribes that you may know one another. Indeed, the most noble of you in the sight of Allah is the most righteous of you. Indeed, Allah is Knowing and Acquainted. (13) }

[Quran, chapter 49, verse 13]

and says:

وَأَنزَلْنَا إِلَيْكَ الْكِتَابَ بِالْحَقِّ مُصَدِّقًا لِّمَا بَيْنَ يَدَيْهِ مِنَ الْكِتَابِ وَمُهَيْمِنًا عَلَيْهِ ۖ فَاحْكُم بَيْنَهُم بِمَا أَنزَلَ اللَّـهُ ۖ وَلَا تَتَّبِعْ أَهْوَاءَهُمْ عَمَّا جَاءَكَ مِنَ الْحَقِّ ۚ لِكُلٍّ جَعَلْنَا مِنكُمْ شِرْعَةً وَمِنْهَاجًا ۚ وَلَوْ شَاءَ اللَّـهُ لَجَعَلَكُمْ أُمَّةً وَاحِدَةً وَلَـٰكِن لِّيَبْلُوَكُمْ فِي مَا آتَاكُمْ ۖ فَاسْتَبِقُوا الْخَيْرَاتِ ۚ إِلَى اللَّـهِ مَرْجِعُكُمْ جَمِيعًا فَيُنَبِّئُكُم بِمَا كُنتُمْ فِيهِ تَخْتَلِفُونَ ﴿٤٨﴾

{ And We have revealed to you, [O Muhammad], the Book in truth, confirming that which preceded it of the Scripture and as a criterion over it. So judge between them by what Allah has revealed and do not follow their inclinations away from what has come to you of the truth. To each of you We prescribed a law and a method. Had Allah willed, He would have made you one nation [united in religion], but [He intended] to test you in what He has given you; so race to [all that is] good. To Allah is your return all together, and He will [then] inform you concerning that over which you used to differ. (48)} [Quran, chapter 5, verse 48]