Interestingly there is no specific rules based on which gender is decided !! So you have to do your guess. As you keep reading, listening Marathi more and more you will now about what is considered what.

Similarly depending on the gender and ending vowel of the word it plural is formed differently.

I have tried to summarize few rules here

GenderEnding vowelPlural form will
end with
Singular –Plural ExampleMeaning in English
Masculineआ (A)ए (e)फळा - फळे
phaLA – phaLe
फुगा – फुगे
phugA – phuge
Board - Boards
Ballon -Ballons
Feminineई (I)या (yA )बरणी - बरण्या
baraNI baraNyA
सावली - सावल्या
sAvalI - sAvalyA
jar-jars
shadow - shadows
Feminineअ(a)आ(A)
ई (I)
माळ – माळा
mAL - mALA
मांजर - मांजरी
mAMjar - mAMjarI
garland - garlands
cat - cats
Neuterअ(a)ए (e)पान – पाने
pAn - pAne
leaf - leaves
Neuterए (e)ई (I)पाते - पाती
pAte - pAtI
blade - blades
Neuterऊ (U)ए (e)पिल्लू पिल्ले
pillU - pille
chick - chicken

Note for Feminine ending with अ(a) there are two ways of creating plural. For some plural ends using आ(A) and for some plural ends with ई (I). There is no specific rule which one to use when. You will understand it as you will read more and more Marathi.

For other words that do not fit in the above rules, the singular and plural forms are same.
e.g. earthen pot is called माठ in Marathi which is treated as masculine. So its plural form is माठ only
e.g. 1 earthen pot 10 earthen pots 1 माठ – 10 माठ

I have started creating list of Marathi nouns, their gender and plural forms. List is uploaded as an excel sheet at
https://sites.google.com/site/learnmarathionline/home/nouns-gender-plural-and-forms-for-prepositions
Download the excel sheet to view it correctly.
Excel sheet is not up-to-date. I will keep adding more and more nouns. So please check this link frequently to see newly added nouns.