Hyderabad-Secunderabad
metro proposed

According to one article, an elevated light rail proposal in the sister cities has "been cleared". Nothing more is available at this time.

A 2 line, 42.6 km intercity commuter rail known as the Metro (MMTS), run by the South Central Railways, is also under construction (see photo). Phase I is due to open in June, 2003. None of the route is underground.

The city is also planning to build a new genuine metro.  The
techno-economic feasibility report has recently been completed by the same company that brought you the Delhi metro.  It consists of a two line, mostly elevated system.  Line 1 will run east to west axis, and line 2 will run on the north-south axis parallel to existing MMTS tracks (phase II) but completely separate from it. Plans have been approved.

IRFCA site report
Hyderabad MRTS unofficial home page
Hyderabad Metro official home page with map
Hyderabad MMTS to open