Now only you have to decide. Under the law it is not permitted for you. Some members have also given scientific reason for the prohibition of such marriages.
If you want a registered marriage, that may not be possible, if you disclose your relationship. Suppressing material information before the marriage registrar is also an offence. But there are so many ways of getting married. You can call a Pandit, pay him adequate dakshina and he will perform your marriage. It is not that you will be arrested on the same day or the next day of the marriage. Someone, who does not like you, or does not like your marriage can give you problem. Some countries may deny you visa.
There is no scientific basis for the opinions given by Member (Account deleted). Sociobiology is really not a science and certainly should not be relied upon for the purpose of deciding whom one can marry. If one has to get really an expert opinion, it should be from a specialist in human genetics. Edward Wilson was an entomologist (study of ants and other insects).
Now all facts and legal position have been placed before you. You can decide for yourself.