First of all, kindly go through Form U. Then your doubts on 6(3) and 4(3) will be cleared. 6(3) is the clause of the form, and the rest is a quotation of that clause.
I have no doubt that the ceiling amount of gratuity is Rs. 10,00,000. But it was not hiked from 'twenty months salary', but Rs. 3,50,000. The original query was whether there is any ceiling regarding monthly salary, viz. 16.5 times. Accordingly, I have quoted what I saw in Form U.
I didn't claim that I have gone completely through the Act. But I am sure that you missed Form U. Without Form U, the Act will not be complete.
Even though there are ceiling limits, an employer can give a higher amount. But normally, provision 10(10) of the Income Tax rule will allow tax exemption up to Rs. 10,00,000.
Regards,
Abbas. P. S.