[GK] When the Districts in Tamil Nadu came into force?

S. No	District	Date of Formation
1	Chennai	01-11-1956
2	Coimbatore	01-11-1956
3	Madurai	01-11-1956
4	Kanyakumari	01-11-1956
5	Ramanathapuram	01-11-1956
6	Salem	01-11-1956
7	Thanjavur	01-11-1956
8	Triuchirappalli	01-11-1956
9	Thirunelveli	01-11-1956
10	The Nilgiris	01-11-1956
11	Dharmapuri	02-10-1965
12	Pudukottai	14-01-1974
13	Erode	31-08-1979
14	Sivagangai	15-03-1985
15	Virudhunagar	15-03-1985
16	Dindigul	15-09-1985
17	Tuticorin	20-10-1986
18	Thiruvannamalai	30-09-1989
19	Vellore	30-09-1989
20	Nagapattinam	18-10-1991
21	Thiruvarur	18-10-1991
22	Cuddalore	30-09-1993
23	Viluppuram	30-09-1993
24	Karur	30-09-1995
25	Perambalur	30-09-1995
26	Theni	25-07-1996
27	Namakkal	01-01-1997
28	Kancheepuram	01-07-1997
29	Thiruvallur	01-07-1997
30	Krishnagiri	09-02-2004
31	Ariyalur	23-11-2007
32	Tiruppur	22-02-2009
33	Tenkasi	22-11-2019
34	Kallakurichi	26-11-2019
35	Ranipet	28-11-2019
36	Tirupattur	28-11-2019
37	Chengalpet	29-11-2019
38	Mayiladuthurai*	-----------------------

* à Mayiladuthari became 38th district of Tamil Nadu, when the government notified it in a gazette on April 07, 2020. Mayiladuthari to be bifurcated from Nagapattinam Dt. 

With the announcement of Mayiladuthurai as a separate district, six new-districts have been created under the regime of the Mr. Edappadi K. Palaniswami-led AIADMK government in the past one year.

Tamil Nadu Districts - Based on their Area 
Tamil Nadu Districts - Based on their Population