The reasons behind the failure of the revolt of 1857 were:
•Firstly,there were no powerful weapons in the hands of Indian kings and rebels..they had the old tradition weapons like sword,arrows,spears,bow etc.
•Most of the parts of the region didn't participated either!
•Thirdly,, They had no system of making a strong conspiracy for the revolt.
• Fourth,and very important reason is because all of them don't know the exact reason behind the revolt!
They didn't knew about one nation,unity in diversity and they just fought for their own matters.
That were the reasons,The revolt was not like that as it should need to be.
Hope that this will help you!!

Reasons for the Failure of the Revolt:

1. Lack of Leadership and Coordination:
The Indian Rebellion of 1857, also known as the Sepoy Mutiny, was marked by a lack of strong leadership and coordination among the rebels. The rebellion was primarily initiated by sepoys (Indian soldiers serving in the British East India Company's army) who were dissatisfied with various grievances. However, there was no unified command or strategic planning, resulting in a fragmented and disorganized revolt.

2. British Military Superiority:
The British had a well-organized and disciplined army, equipped with modern weapons and superior military tactics. They quickly mobilized their forces to suppress the rebellion. The rebels, on the other hand, lacked proper training, weaponry, and strategic planning, making it difficult for them to withstand the British military might.

3. Lack of Support from Princely States:
The revolt failed to gain significant support from many princely states, who either remained neutral or actively supported the British. These states were hesitant to join the rebellion due to their own political interests or fear of British reprisal. The lack of unified support from princely states weakened the rebels' position and hindered their chances of success.

4. Religious and Regional Divisions:
While the revolt was initially triggered by the issue of the greased cartridges that offended both Hindu and Muslim soldiers, religious and regional divisions also played a role in the failure of the rebellion. The rebels were not able to overcome deep-seated religious and regional differences, which weakened their unity and hindered their ability to mount a cohesive resistance against the British.

5. Lack of Mass Support:
Although the rebellion had pockets of local support, it failed to gain widespread popular support from the general Indian population. Many people remained apathetic or apprehensive about joining the revolt due to a fear of British reprisal or uncertainty about the outcome. The lack of mass support limited the rebels' resources and made it difficult for them to sustain the rebellion.

6. British Divide and Rule Policy:
The British effectively exploited existing divisions within Indian society through their "divide and rule" policy. They capitalized on the differences between Hindus and Muslims, as well as various regional and caste-based divisions, to undermine the rebellion. This policy further fragmented the rebels' unity and weakened their resistance.

7. British Military Reprisals:
The British responded to the rebellion with brutal force and unleashed a series of military reprisals. They systematically crushed the rebellion, inflicting heavy casualties and imposing severe punishments on the rebels. The ruthless suppression of the revolt further demoralized the rebels and deterred others from joining the cause.

In conclusion, the failure of the Indian Rebellion of 1857 can be attributed to a lack of leadership and coordination, the British military superiority, the lack of support from princely states, religious and regional divisions, the lack of mass support, the British divide and rule policy, and the brutal military reprisals by the British. These factors combined to weaken the revolt and ultimately led to its failure.