Srimathe Rangaramanuja Mahadesikaya Namaha
Srimathe SriVarAha MahAdEsikAya Namaha
Sri Velukkudi Krishnan Swamy Thiruvadigaley Sharanam
What is Dheekshai? Is it the same as samAshrayaNam?
Better to take instruction only from our family vAdhyAr swami as there are so many versions told/followed by different families.
As much as I know, deekshai is usually observed after the death of parents. It should be observed for a chosen period of 12 days (at least) or 1 mandalam or 1 year.
But observing deekshai is not that easy. I have heard through others that we will have to observe the following.
There might be more such restrictions or edits to my list and your question is best to be answered by vedic scholars and champions like Velukkudi Swami only.