Maintenance Under Section 125 Of CrPC

Dear Sir, I am 33 years old working in pvt sector company. I born in 1985 to my father Mr Basavaraj & My mother Smt Soubhagya. My mother expired in 1992 at that time I was 7 years and my sister is 5 years old. My father got remarriage in 1993 to Smt Nagaveni and now they have one daughter (Current age 19 years). I started working after completion of my PUC in 2002 and continued my graduation and master graduation with the help of study loan from syndicate bank and recently i paid it completely. I got married in 2015 to Anjanadevi and currently have one child (1 year old). Since from beginning my step mother was very interested in the money which i earn and i use to give everything to them till my marriage. I purchase one plot at bellary with my hard earned money and my step. mother registered the land in her name by blocking me sentimentally. and they have own resident also at sandur. now they are in sandur in their own house and running hotel for income. after my marriage they have not come to see me and not performed any of their responsibilities during miscarriage happened to my wife twice and continuously damaging my image in relative spreading wrong message. Initially i was paying some amount as feeling it is my responsibility but later i stopped sawing their attitude. Now they have sent legal notice to me asking for maintenance claim. Please clarify on what ground court will decide maintenance amount and does my step mother is eligible for the same?