Pt Sri Pranesh Achar (Ananda Rangan)
Pooja
The answer to this is found in the scripture Vishnu Dharmottara. It states:
After performing the morning Sandhyavandana and worshipping Gayatri, one should remain standing until sunrise and chant Gayatri Mantra. Then, facing the East, seated, and in the evening facing the West, the twice-born (Dvija) should perform the daily worship. After completing the morning worship, one should perform Brahma Yajna.
From this, it becomes clear that:
After completing the morning Sandhyavandana, one should chant the Narayana Mantra three times for every Gayatri Mantra recited in Sandhyavandana. After that, one should perform the morning Agnikarya.
Whether one is a Brahmachari or a Grihastha, after completing their daily worship (Upasana), Brahma Yajna must be performed.
Only after completing Brahma Yajna, one should perform the Madhyanika Sandhyavandana.
Thus, the correct order is:
Morning Sandhyavandana → Upasana → Brahma Yajna → Madhyanika Sandhyavandana.
