Devesh Kapur and Arvind Subramanian, writing in the Business Standard:

In principle, there are five ways of financing additional expenditures over the next 12 months or so:

• Reduction in other expenditures (Rs 1-1.5 trillion)
• Foreign borrowing, from official sources and non-resident Indians (NRIs; Rs 1-1.5 trillion)
• Public financing by issuing g-secs (including to banks and LIC) (Rs 5 trillion)
• Monetary financing or “printing money” (Rs 1-1.5 trillion)
• Mobilizing additional resources via raising taxes and cutting subsidies (Rs 1-1.5 trillion)

The rest of the article explains their rationale behind each point above. Essential reading!