What was the name of Valmiki's father

Who are Nala and Nila in Ramayan?

Who are Nala and Nila in Ramayan?

Nala

अयम् सौम्य नलो नाम तनुजो विश्व कर्मणः |

पित्रा दत्त वरः श्रीमान् प्रतिमो विश्व कर्मणः || 6.22.50

(God of the Sea to Lord Shri Rama) O, excellent man! This, Called Nala , a wonderful person, he is Son of Vishvakarma ; who has received a blessing from his father and is equal to Visvakarma.

Nala was the creator of the bridge (Rama Setu or Nala Setu). -Valmiki Ramayana 6.26.21

Nala fought in an extraordinary duel with Pratapana. -Valmiki Ramayana 6.43.23

This virtuous Nala quickly brought water from the sea to Lord Sri Ramas Rajatilak. -Valmiki Ramayana 6.128.57

Nila

पावकस्य सुतश्श्रीमान् नीलोऽग्निसदृशप्रभ:।

तेजसा यशसा वीर्यादत्यरिच्यत 17/11/12 ।।

Nila (Neela), the wealthy Son of Agni, the fire god, who equaled him in appearance, surpassed other monkeys in energy, prestige and ability.

Nila was the ape army general. -Valmiki Ramayana 6.3.32 / 6.59.72

Nila was one of only four great apes (Angada, Nila, Sugriva, and Hanuman) who were able to cross the ocean. -Valmiki Ramayana 5.2.30

Prahasta, the army chief of Rakshasas, was killed in the Battle of Nila. -Valmiki Ramayana 6.59.1

Who are her parents?Are you two brothers and twins?How did they come up with names similar to Nala and Nila?

Their parents of monkeys are unknown. Their devas fathers were different Vishvakarma and Agni, as described above.

I'm not sure about twins but they could be brothers (this could be the same as Sugriv (sun of Surya) and Bali or Vali (son of Indra) were brothers since their father (Riksharaja who was also their mother) of monkeys was the same). .

Ramcharitmanas says:

जामवंत बोले दोउ भाई। नल नीलहि सब कथा सुनाई ।।

राम प्रताप सुमिरि मन माहीं। करहु सेतु प्रयास कछु नाहीं ।।

How did you meet Lord Rama?

After Bali's death, his brother Sugriva became the monkey king. He later asked all the monkeys to join Rama's army.

How could they make stones float on the water while building Ram Setu?

The bridge was not only built from stones, but from trees, rocks and mountains (source). The floating stone theory doesn't seem 100% true, but the great work of an engineer / architect. Nala was the son of Vishvakarnma (the great architect of Devas) and learned the art from his father. This is what Nala says herself in Valmiki Ramayana:

मम मातुर् वरो दत्तो मन्दरे विश्व कर्मणा |

औरसस् तस्य पुत्रो अहम् सदृशो विश्व कर्मणा || ६-२२-४९

Visvakarma gave my mother the following blessing on Mount Mandara: "O godlike woman! A son like me will be born to you.

औरसस्तस्य पुत्रोऽहम् सदृशो विश्वकर्मणा |

स्मारितोऽस्म्यहमेतेन तत्त्वमाह महोदधिः || ६-२२-५०

न च अपि अहम् अनुक्तो वै प्रब्रूयाम् आत्मनो गुणान् |

I am a son born from Visvakarma's own loins. I am equal to Visvakarma. This god of the ocean reminded me. The great ocean spoke the truth. Since I have not been asked, I have not yet given you my details.

समर्थ्श्चाप्यहम् सेतुम् कर्तुम् वै वरुणालये || ६-२२-५१

तस्मादद्यैव बध्नन्तु सेतुम् वानरपुङ्गवाः |

I can build a bridge over the ocean. So let the first monkeys build the bridge themselves now.

Note:

Ramcharitmanas says the bridge was built by both Nala and Neela:

सैल बिसाल आनि कपि देहीं। कंदुक इव नल नील ते लेहीं ।।

बाँधा सेतु नील नल नागर। राम कृपाँ जसु भयउ उजागर ।।

But after Valmiki Ramayana the bridge of Nala was built, hence it is called Nala Setu in many places:

दशयोजनविस्तीर्णम् शतयोजन मायतम् || 6.22.74

ददृशुर्देवगन्धर्वा नलसेतुम् सुदुष्करम् |

The heavenly ones and Gandharvas, the heavenly musicians, saw Nala's Bridge ten yojanas wide and a hundred yojanas long, which was very difficult to build.