our NGO(animal welfare) have contract with municipal corporation before GST.

rate of contract as per that time but now they says to register under GST.

if so then its not economical to us what to do. 

Also we didn't know is GST is applicable to us or not? because this NGO DO WORK OF ANIMAL BIRTH CONTROL OF STRAY DOGS. and its totally for animal welfare.

ALSO we not have 12AA registration certificate.

pls suggest what to do?