Kool kayda means? 

As far as Agriculture Land is concerned, there is no such thing a Tenancy.   Agriculture land, by law, is meant for sustaining livelyhood, but only for the owner.  Besides the registered owner, nobody else derives any right on the agricultural land.

What does the word Kool mean I think it is a word in local language??

persons who are lawfully cultivating the land of the others are considered as a deemed tenant under the act

2)t he said act declared 1 April 1957 as a tillers day and persons who are tenant or cultivating the land of others on 1 April 1957 (tillers day)are deemed to have purchased land .

3)  Kul Kayda, is a provision of protection given to the tenants of the land under the Bombay Tenancy and Agricultural Act 1948. U/s 43 of the said Act any land acquired by a tenant shall not be entitled to sell, transfer the said land without the prior approval of the Collector.

4) if you are not cultivating other land you cannot be look of other property owners 

He can cultivate the land of other on there mutual.agreement and can give there share in agroculagri produce if the person himself is not cultivating his own land .

He can cultivate land of others and be tenant 

By going through the 7/12 extracts or the village land records, it is easy to find out the property details. In the 7/12 extracts it is mentioned whether the property is affected by the kul kayada or your property was tenanted property. Tenanted property (kul Kayada) means your forefathers (ancestors) had leased /given the land to other persons to cultivate and in turn they were getting rent for it. 

The Bombay Tenancy and Agricultural Land Act 1948's objective is “land to the tillers”. Those persons who are lawfully cultivating the land of the others are considered as a deemed tenant under the act. The said act declared 1 April 1957 as a tillers day and persons who are tenant or cultivating the land of others on 1 April 1957 (tillers day)are deemed to have purchased land . Thus, Kul Kayda, is a provision of protection given to the tenants of the land under the Bombay Tenancy and Agricultural Act 1948. U/s 43 of the said Act any land acquired by a tenant shall not be entitled to sell, transfer the said land without the prior approval of the Collector. 

You can ascertain the facts and  decide further course of action

In spite of cultivating his own farm of joint family and having sufficient income can he still cultivate land of other owners and become kool of others?

There is no wrong in it.
Sec. 32A limits the right of a tenant holding other Lands to such area only which will raise his holding to the extent of the ceiling area.