Step 1: Understand "Local Self-Government".
Local Self-Government refers to the management of local affairs by representatives elected by the local people themselves. In India, this means Panchayats in rural areas and Municipalities in urban areas.
Step 2: Recall the history.
While these institutions existed before, they did not have constitutional status, which made them weak and dependent on state governments. To strengthen them and make them uniform across the country, two major constitutional amendments were passed in 1992.
Step 3: Identify the specific amendments.
(S) The 73\textsuperscript{rd Constitutional Amendment Act, 1992}, gave constitutional status to the Panchayati Raj Institutions (for rural areas). It added a new Part IX and the 11th Schedule to the Constitution.
(T) The 74\textsuperscript{th Constitutional Amendment Act, 1992}, gave constitutional status to Urban Local Bodies (Municipalities, for urban areas). It added a new Part IX-A and the 12th Schedule to the Constitution.
Together, these two amendments are considered revolutionary for bringing democracy to the grassroots level.