Hey Rudranksh,
Her are the things to do and Places to see in Ratnagiri :-
Ratnadurg fort
Bhatye beach
Titanic view point
Mandwi beach also called as gateway of Ratnagiri
Mirkarwada Village
Ganpatipule beach
Aare-Ware twin beaches
Thibaw point and thibaw palace
Bala gangadhar Tilak birth place
Hope you can visit all these Places ....
Happy Travelling Bro!!!