Having played cricket for more than half a decade, i think i  am eligible to answer this question. I used to play professional cricket in Indore which is a district called as a division in cricketing parlance. Moving on to the steps, here are they:

STEP 1: You get yourself enrolled in a local club where you start learning the tricks of the trade. If the authorities like you as a player, they draft you into their team which plays at various levels, senior being the highest and under-10/12 being the lowest. These tournaments in which you play are association sponsored and a good performance can elevate you to the next level. 

STEP 2: A division consists of various districts. Firstly, selection trials are held at district levels but in most cases, teams are selected on the basis of performance in the local tournament. Then Inter-district tournament takes place which is a mere formality  because of the less-developed cricketing infrastructure.

STEP 3: After Inter-district tournament, selectors once again review the performance and if anyone from other districts have performed exceptionally well, they pick him up and draft into the divisional side which takes part in Inter-divisional tournaments. These Inter-divisional tournaments are held at various levels and to enter into a Ranji Side, Senior Divisional Tournaments pave the way. 

But those who perform exceptionally well at junior level also gets the chance to get selected in Ranji Trophy teams. 

STEP 4: After Inter-divisional tournaments, the player who perform are picked up by selectors and are called up for a camp. In most states, they are selected through trials also but performance is the major criteria in selection. These selected players train under watchful eyes of state association coaches (mostly International players) and tour to various side tournaments which act as a preparatory tournaments before Ranji Trophy. 

STEP 5: If you perform well-enough in these tournaments, your selection chances becomes high and in the end, selectors announce the Ranji Trophy team. 

This is the process to get selected..........easier said than done though......!!!!!!!