What is the current base year of IIP?

The current base year of IIP is 2011-12. Fertilisers, Natural gas, cement, coal, crude oil, refinery products, steel, electricity are the eight core industries which comprise around 40% of the weight of items included in the Index of Industrial Production (IIP). You can read about the Index of Industrial Production [UPSC Economy Notes] in the given link.

The Quick Estimates of Index of Industrial Production (IIP) are released on 12th of every month. 

Further readings:

1. Merger of NSSO and Central Statistical Office (CSO) to form National Statistical Office (NSO)
2. Core Sectors of the Indian Economy