Doraka means a yellow thread that will be tied onto the right hand of the one who performs the Pūjā. Granthi means knot. Take one yellow coloured thread and make nine knots in equidistance from each other. After making knots, the thread is called doragranthi (knotted thread). Place this in pūjā by reciting the following mantra. This is known as dorasthāpanam (establishing doragranthi).

बालभानुप्रतीकाशे पूर्णचन्द्रनिभानने। सूत्रेऽस्मिन् सुस्थिता भूत्व प्रयच्छ बहुलान् वरान्॥

bālabhānupratīkāśe pūrṇacandranibhānane | sūtre'smin susthitā bhūtva prayaccha bahulān varān ||

After completing the entire pūjā, doragranthi is worshiped and this is called doragranthi pūjā. Each of these nine knots are worshiped with the following mantra.

1. कमलायै नमः प्रथमग्रन्थिं पूजयामि। kamalāyai namaḥ prathamagranthiṁ pūjayāmi |

2. रमायै नमः द्वीतीयग्रन्थिं पूजयामि। ramāyai namaḥ dvītīyagranthiṁ pūjayāmi |

3. लोकमात्रे नमः तृतीयग्रन्थिं पूजयामि। lokamātre namaḥ tṛtīyagranthiṁ pūjayāmi |

4. विश्वजनन्यै नमः चतुथग्रन्थिं पूजयामि। viśvajananyai namaḥ catuthagranthiṁ pūjayāami |

5. महालक्ष्म्यै नमः पञ्चमग्रन्थिं पूजयामि। mahālakṣmyai namaḥ pañcamagranthiṁ pūjayāami |

6. क्षीराब्धितनयायै नमः षष्ठमग्रन्थिं पूजयामि। kṣīrābdhitanayāyai namaḥ ṣaṣṭhamagranthiṁ pūjayāami |

7. विश्वसाक्षिण्यै नमः सप्तमग्रन्थिं पूजयामि। viśvasākṣiṇyai namaḥ saptamagranthiṁ pūjayāami

8. चन्द्रसहोदर्यै नमः अष्टमग्रन्थिं पूजयामि। candrasahodaryai namaḥ aṣṭamagranthiṁ pūjayāami

9. हरिवल्लभायै नमः नवमग्रन्थिं पूजयामि। harivallabhāyai namaḥ navamagranthiṁ pūjayāami |

Having thus worshiped all the nine knots, the thread is to be tied in the right hand of the woman who is doing the pūjā. This can be tied by the senior most woman of the family or by her husband, if no elders are available. At the time of tying the knot, the following mantra is to be recited.

सर्वमङ्गलमाङ्गल्ये सर्वपापप्राणाशिनि। दोरकं प्रतिगृह्णामि सुप्रिता भव सर्वदा॥

sarvamaṅgalamāṅgalye sarvapāpaprāṇāśini | dorakaṁ pratigṛhṇāmi supritā bhava sarvadā ||

Doragranthi Puja in Varalakshmi Vratham

Further Readings:

Arghya in Ganesh Puja

Laghaya Navavarana Puja

Shivaratri Puja

Sri Chakra Navavarana Puja