JUDGMENT

THOMMEN, J.:— The appellant, the East India Corporation Limited, is the defendant in O.S. No. 623 of 1980, which is a suit instituted by the respondent, Shree Meenakshi Mills Limited, for recovery of possession of a building on the ground of arrears of rent, etc. The respondent-plaintiff alleged that the appellant-defendant was the tenant of the building in question and that it has not paid the agreed rent of Rs. 900/ -per month for a long period, despite persistent demands, and has thus been in "wilful default" of payment of the agreed rent. The appellant denied these allegations. It specifically denied any relationship of landlord and tenant between the parties, and contended that its occupation of the building was not as a tenant of the respondent, but as one of the "associates" or "co-sharers" or "co-owners". The suit was decreed. The decree of the learned Munsif was affirmed in appeal by the first appellate Court as well as by the High Court. All the three Courts, rejecting the appellants contentions to the contrary, found that it was a tenant of the respondent; it questioned without bona fide the respondents title as landlord; it was in default of payment of rents, and, it was liable to be evicted from the building. Against these concurrent findings, the present appeal was brought to this Court by means of a special leave petition. Leave was granted by order of this Court dated 24-9-1984.

2. At the time of the institution of the suit or the grant of leave by this Court, the building in question did not come within the purview of the Tamil Nadu Buildings (Lease and Rent Control) Act, 1960 (the Act) for the agreed rent, as alleged by the plaintiff respondent and as found by all the Courts, was Rs. 900/- per month, and as such was outside the limit prescribed under S. 30(ii) of the Act for a residential building to fall within the statutory ambit. S. 30, as it stood at the relevant time, stated :-

"30. Exemption in the case of certain buildings.- Nothing contained in this Act shall apply to-

(i) any building for a period of five years from the date on which the construction is completed and notified to the local authority concerned; or

(ii) any residential building or part thereof occupied by any one tenant if the monthly rent paid by him in respect of that building or part exceeds four hundred rupees.

. . . . . . . . . . . . . . . . . . . . . . . . . . ."

3. Clause (ii) of S. 30 was, however, struck down by this Court in Rattan Arya v. State of Tamil Nadu (1986) 3 SCC 385. This Court- stated:

"..... Section 30(ii) of the Tamil Nadu Buildings (Lease and Rent Control) Act, 1960 has to be struck down as violative of Art. 14 of the Constitution. A writ will issue declaring S. 30(ii) as unconstitutional".

As a result of this declaration of the constitutional invalidity of S. 30(ii), the Act in question, according to the appellant, has to be read as if Cl. (ii) of S. 30 was never brought into force, and consequently all residential buildings, which are older than five years (see C1 (i) of S. 30) and let out for whatever rent, came within the ambit of the Act. Accordingly, although the suit was properly instituted in the Civil Court without regard to the special provisions of the Act, it is now contended that as a result of the declaration by this Court of the constitutional invalidity of Cl. (ii) of S. 30, which excluded from the purview of the Act any building or part thereof let out on a monthly rent of R.S. 400/ -, the decree of the Civil Court, whatever be the merits of the findings on the respective contentions of the parties, has become null and void and of no effect whatever. This contention of the appellant is based on the principle that any decree passed by an incompetent Court is a nullity. The appellants counsel relies on the principle reiterated by this Court in Sushil Kumar Mehta v. Gobind Ram Bohra (1990) 1 SCC 193 and the earlier decisions referred to therein on the point. In Kiran Singh v. Chaman Paswan (1955) 1