Describe the main reason of development …

The main factors that led to the rise of Buddhism and Jainism in India are the following:

1. Rigid Caste System: in the social hierarchy the priests were on the top and the shudras were on the bottom. The shudra or the fourth Varna people were not allowed to perform the Vedic rituals and they were banned to chant the Vedic mantras.

2. The new coinage: the traditional people opposed the use of coinage. They preferred the traditional barter system instead of coinage.  

3. Language barrier: the Vedas were written in the Sanskrit (which was a language of upper varnas), this was not the language of common people. Therefore, the third and fourth Varna people could not understand the beliefs of Vedas. Therefore, they wanted a religion which would be accessible for all Varna people.

The main tenets of Jainism are the following:

1. Truth - Satya

2. Non-violence - Ahimsa

3. Celibacy/Chastity - Brahmacharya

4. Non-stealing - Achaurya or Asteya

5. Non-attachment/Non-possession - Aparigraha

The main tenets of Buddhism are the following:

1. The Three Universal Truths;

2. The Four Noble Truths; and

3. The Noble Eightfold Path.