Raja Yoga - Prerequisites

ALL are eligible for "Karma Yoga" there are no specific pre-requisites specified.

But for Raja Yoga there are few pre-requisites.
1. The aspirant should have good mastery over the external senses and attained "skill in action" by performing the Karma Yoga.

2. The person still has a lot of predominant quality of "rajas" - inclined towards action. (A large balance either +ve or -ve in the account)

Lord Declares:
स्पर्शान्कृत्वा बहिर्बाह्यांश्चक्षुश्चैवान्तरे भ्रुवोः।
प्राणापानौ समौ कृत्वा नासाभ्यन्तरचारिणौ।।5.27।।
sparśānkṛtvā bahirbāhyāṅścakṣuścaivāntarē bhruvōḥ.
prāṇāpānau samau kṛtvā nāsābhyantaracāriṇau..5.27..

यतेन्द्रियमनोबुद्धिर्मुनिर्मोक्षपरायणः।
विगतेच्छाभयक्रोधो यः सदा मुक्त एव सः।।5.28।।
yatēndriyamanōbuddhirmunirmōkṣaparāyaṇaḥ.
vigatēcchābhayakrōdhō yaḥ sadā mukta ēva saḥ..5.28..

Instruction 11: (Meaning of above two verses)
Keeping external objects outside (bahih, sparsan, bahihi kritva),
keeping eyes fixed at the middle of eyebrows (chaksus, ca, eva, antere bhruvau)
Keeping equal breathing cycles that move through the nostrils (prana-apana samau krutva nasa abhyantara carinau)
The contemplating one (munih),
fully intent only on liberation (moksha parayana)
Who has control over the indriyas, manas and buddhi (yata-indriya-mano-buddhi)
free from desire, fear and anger (vigata-iccha-bhaya-krodha)
He is verily always free! (yah-sada-mukta-eva-sah)

The Karma Yoga helps one win over the quality of Tamas (inertia) and its products called external sense objects by mastering the indriyas (organs), which are predominantly of "rajas" nature by freeing them from the clutches of their respective sense objects (vishayas).

The Raja Yoga helps one win over the quality of Rajas, by mastering the manas (mind, predominantly Sattvik - illuminating nature) by freeing it from the clutches of desire, fear and anger.

Predominantly sattvik nature aspirants, having mastered the Karma Yoga can directly move to "Bhakti Yoga" skipping Raja Yoga.

Regarding the eligibility, wise men say "A person who is thirsty can only be eligible for drinking water!"

In case of Karma Yoga, an aspirant is asked to do "HIS OWN DUTY" and nothing new. Just the attachment to the fruit of action to be surrendered to the LORD. There is no training required to practice the Karma Yoga. Everybody is eligible. {in fact everybody MUST practice it}

Warning: Never try to practice "Raja Yoga" without a "living realized Guru" - It may prove counter productive in some cases because one need to take up practice of "eight limbs of Yoga" that forcibly control various internal energies of the aspirant (the energy of resolve,the energy of knowing and the vital force). If not managed with a proper balance it may cause the friction within.

There are other simpler methods like "Naama Japa" that can achieve the same result without force. Lord directs an aspirant to the right GURU when the aspirant is successful in KARMA YOGA!

om tat sat