Multiple business units

Is it allowed to have multiple business units under 1 private limited company? Is it mandatory to split business unit transactions/incomes? I have 3 business units property income, software income and trading income. Is there a combined tax implication or should I pay income tax on individual business units? Is there a special provision in income tax act which prescribes premises income to be sperated and calculated income tax seperately?

 

Any thoughts. Appreciate early response and advance thanks.

 
Thanks for the reply. Can I set off annual business losses against other business units?  Say loss from trading against profit from rental income? NOT long term capital gains.

Thanks again