He began his career as working for Adina Beg, who appointed him a risaldar (cavalry commander) and in 1752, rebuilt the damaged fort.

[3][9][a] Mir Mannu (Mu'in ul-Mulk), the Governor of Lahore, was worried about the increasing power of the Sikhs so he broke the peace.

Mir Mannu also ordered Adina Beg, the Faujdar (garrison commander) of the Jalandhar region, to begin killing the Sikhs.

In order to develop good relations with the Sikhs, he sent secret messages to them who were living in different places.

[11] This position helped him develop good relations with Dewan Kaura Mal at Lahore and assign important posts to the Sikhs in the Jalandhar division.

The Governor of Lahore ordered an attack on Ram Rauni to kill the Sikhs staying in that fort.

Beg was well acquainted with the strength of the Sikhs and he feared they would oust him if he allowed them to grow stronger, Adina Beg send a strong army under Mir Aziz Bakshi, the Sikhs took up refuge in the Ram Rauni fort, Jassa Singh Ramgarhia, Jai Singh Kanhaiya and other Sikh chief's were in the fort, Jassa Singh and Jai Singh Kanhaiya made several sallies and sorties and killed numbers of besiegers, but they had to evacuate the fort in the end,[16] In 1758, After the death of Adina Beg he collaborated with Jai Singh Kanhaiya, and captured Sri Hargobindpur, and Miani and established his headquarters at Sri Hargobindpur.

[17] In 1765, Ahmad Shah Durrani invaded India for seventh time in the winter of 1764–1765, During this campaign he constantly harassed by Sikhs, Qazi Nur Muhammad who was present in the Afghan Army describes the numbers of engagements between Sikhs and Afghans, a battle was fought on the western bank of the Satluj opposite Rupar, it was morning and the Afghan army was hardly gone 3 km from the western bank of the Satluj, when they attacked by the Sikhs, The Afghans immediately stopped marching and got into regular formation of battle, Ahmad Shah Durrani was in the center with 6,000 choice soldiers, Shah Vali Khan, Jahan Khan, Shah Pasand Khan, Anzala Khan and others at the head of 12,000 troops were on the right Nasir Khan with 12,000 Baluchis was on the left, The Dal Khalsa also organised themselves in regular battle army Jassa Singh Ahluwalia fearlessly stood like a mountain in the center close by him was Jassa Singh Thokah, looking like a lion in stature, the Qazi says that Ramgarhia has his own flag and war drum[18] In 1767, Ahmad Shah Durrani Invaded India for the eight time, while Ahamed Shah was crossing the river Beas, his passage was obstructed by Jassa Singh Ahluwalia and Jassa Singh Ramgarhia, a fierce contest took place in which Ahluwalia was severely wounded.

Jassa Singh Ramgarhia gave a staunch resistance, but the pressure from the attackers compelled him to leave the Trans-Sutlej area.

Jassa Singh Ahluwalia had advised him not to block the Ramgarhia retreat over the river or interfere with their flight.

[27] While at Sirsa, Jassa Singh’s men accidentally lost a couple of brass buckets while drawing water from a well, which was about 100 feet deep.

When a man was lowered into the well, he found four iron boxes filled with gold coins worth around three or four lakhs.

With the Bhattis defeated, he established his headquarters at Tosham, where he could easily hide in the local hill and raid the Delhi region.

[27][24][26]While staying at Tosham, a Brahman complained that a Muslim officer from Hisar had abducted his married daughter.

In March 1783, he come to know that Dal Khalsa under Jassa Singh Ahluwalia was advancing upon Delhi, he joined it at March 10, 1783, On 11 March, Dal Khalsa entered in the royal palaces in the Red Fort, In the Diwan-i-Am Jassa Singh Ahluwalia was placed on the throne of Delhi as Badshah Singh of Delhi by Sikhs, Through Ramgarhia was in minority, yet he challenged the Ahluwalia and called upon him to get down immediately.

Both sides drew out swords and were about to pounce upon each other when Jassa Singh Ahluwalia at once renounced the honour, Ramgarhia detached the throne of Mughal emperor Aurangzeb (on which he ordered the death of 9th guru Guru Teg Bahadur) and brought it on elephants and kept it at Golden Temple, Amritsar.