Is the segregation of dry waste and wet waste mandatory in housing societies?

While it is always advisable to segregate waste at source, it is not yet mandatory for every housing society in Mumbai.
MCGM is making segregation of waste at source mandatory for all housing societies that fall under a certain criteria like:

• All complexes having a built up area of 20,000 sq.m and above
• All complexes having a built up area of 5000 sq.m and above
• All complexes having a built up area of 2000 sq.m and above being constructed after 02/04/2016 and 
• Bulk waste generators or housing societies generating waste of more than 100 kgs/day

The directive by the civic authorities has been described in detail here.