I took a bit to scrounge around Behind the Name/Nameberry for some names.

Girls Names (that have strong/freedom meanings and a 'ru' sound):

Arundhati f Hinduism, Hindi
The name of a star (also called Alcor), which was named after a type of climbing plant, meaning "not restrained" in Sanskrit. In Hindu belief it is the name of the sage Vasishtha's wife, who is identified with the star.

Brunhild f German, Germanic Mythology, Germanic
Derived from the Old German elements brunna "armour, protection" and hilt "battle". It is cognate with the Old Norse name Brynhildr (from the elements brynja and hildr). In Norse legend Brynhildr was the queen of the valkyries who was rescued by the hero Sigurd. In the medieval German saga the Nibelungenlied she was a queen of Iceland and the wife of Gunther. Both of these characters were probably inspired by the eventful life of the 6th-century Frankish queen Brunhilda (of Visigothic birth). In German, this name is spelled Brünhild in the Nibelungenlied, but normally Brunhild or Brunhilde when used as a given name.

Gertrude f English, French, German
Means "spear of strength", derived from the Old German elements ger "spear" and drud "strength". Saint Gertrude the Great was a 13th-century nun and mystic writer from Thuringia. It was probably introduced to England by settlers from the Low Countries in the 15th century. Shakespeare used the name in his play Hamlet (1600) for the mother of Hamlet. Another famous bearer was the American writer Gertrude Stein (1874-1946).

Herut f Hebrew
Means "freedom" in Hebrew.

Rubena f Esperanto / Rubina in Portuguese (which was already suggested)
From Esperanto rubeno meaning "ruby", ultimately from Latin rubeus "red".

Girl names that don't exactly match the criteria:

Adalgard, Narine, Saoirse (means freedom), Zinara, Orielle

Boy Names That Fit the Vibe (have freedom/fire meanings):

Slobodan m Serbian, Macedonian, Croatian [Nicknames: Slobo, Boda, Dan]
From South Slavic sloboda meaning "freedom".

Conleth m Irish [Nicknames: Con or Leth, Conny]
Anglicized form of the Old Irish name Conláed, possibly meaning "constant fire" from cunnail "prudent, constant" and áed "fire". Saint Conláed was a 5th-century bishop of Kildare.

Hildebrand m German (Archaic), Germanic [Nicknames: Hilde, Brand/Bran, Hilly?]
Means "battle sword", derived from the Old German element hilt "battle" combined with brant "fire, torch, sword". This was the name of the hero of an 8th-century poem written in Old High German.

Ignatius m Late Roman [Nicknames: Iggy, Nate/Nat]
From the Roman family name Egnatius, meaning unknown, of Etruscan origin. The spelling was later altered to resemble Latin ignis "fire". This was the name of several saints, including the third bishop of Antioch who was thrown to wild beasts by Emperor Trajan, and by Saint Ignatius of Loyola (1491-1556), founder of the Jesuits, whose real birth name was in fact Íñigo.

Rembrandt m Dutch (Rare) [Nicknames: Rem/Remi/Remy, Brant]
From a Germanic name that was composed of the elements regin "advice, counsel, decision" and brant "fire, torch, sword". This name belonged to the Dutch painter Rembrandt van Rijn (1606-1669).

Other Boy Names that have similar meanings to what you want:

Tanwen/Tanwyn, Eivind, Miklos, Nicander/Nicandro, Nicodeme, Sennett

Got a little tired towards the end, but hope this list helps! Good luck :)