Can I, as a 38-year-old OBC, appear for NEET or government exams?

I’am 28 yrs old and an elder sister in my 4 member family. Financially we belong in upper middle class but my strict father raised us in middle class standard. After school i got my higher education from government college and around 24yr old i stopped asking money from my father. I asked only for basic minimum to cover my travel experience, that too killed me with shame and heavy burden on my chest. I worked really hard to crack SSC exam and in sep i joined my office after clearing exam by the grace of god. Now here comes my 1st salary and my younger brother demanded that i pay 799 for his phn recharge, which i declined and then later in the evening he is demanding that he is buying someone, he is in the shop so give me 200rp without any explanation of what he is buying. I don’t want to do that but now my mother is lecturing me about relations over money and that its ok, you are ought to give money to ur brother. Now m the villian only because I don’t want to pay for his expenses. M not against giving money in need but is it wrong for me to decline to become ATM for my younger brother? And what should i give him money for, it was my parents who sacrificed for me not him. What should i do when m being forced to treat him like a son by my mother rather than just a sibling?