Regarding name change and pan card issue

Myself Poorna from Chennai in all my school and college certificate name is mentioned as Nagabushanam Poorna E and I got married vsince 2 yrs now my in law want to change my name as Poorna NandhaKumar ( husband name). Does it affect my future government job opportunities .my age is 30. If yes then what I have to do or else if no what is the procedure to change and how?. And one more issue my twin sister name is Nagabushanam Poornima E we both have applied for pan card 11 yrs ago but we both got same pan number after noticing it my dad applied for a new card stating this issue but again we got same number. When I enquired IT customer care service they said currently that pan number is holding my sister name only. But aadhar card linked with it is mine. Currently we both are facing a problem. Myself unemployed but my sister working for the past 8 yrs. So how to overcome from this issue. And what is the solution for it. Whether I can use that pan number and open bank account I don't know. Please help me in this issue