Can Rajya Sabha reject a bill?

Rajya Sabha cannot amend or reject a money bill. It should return the bill to the Lok Sabha within 14 days, either with recommendations or without recommendations. 

If the Rajya Sabha does not return the bill to the Lok Sabha within 14 days, the bill is deemed to have been passed by both the Houses in the form originally passed by the Lok Sabha. 

In cases of the ordinary bill, constitutional amendment bill and financial bills (involving expenditure from the Consolidated Fund of India), Rajya Sabha enjoys equal status with Lok Sabha regarding the introduction and passage of bills. 

Further Reading:

• Types & Stages of a Bill 
• Lapsing of Bills
• Constitutional Amendment Process in India

To read more about the Assent to Bills, check the linked article.