Brief Answer:
This is delayed motor development

Detailed Answer:
Hello sir

Thanks for the query
I can understand your problem.If a child is not able to crawl or stand without support at age of 18 months,this suggests delayed motor development.

The development of a child should be assessed under different aspects like motor(both gross motor and fine motor),social and verbal.
As you have mentioned the motor milestone is delayed but I would like to know for others like verbal and social.
There are red flag signs for assessment of development and one or more red flag signs in any area indicates delayed development.
At 18 months of age the red flag sign of SOCIAL development is lack of interest in playing and interacting with others. Similarly in COMMUNICATION or VERBAL development unable to say clear words or to understand short requests like where is your mom; in FINE MOTOR and COGNITIVE development not holding or scribbling with crayons or unable to make block towers and in GROSS MOTOR unable to stand without support or attempt of walking all these are red flag signs.
It may be possible that there may be developmental delay in all aspects or only in motor aspect only.
From the picture it appears to me that he is well interested in playing and is also interactive. He can sit without support with a good hand grip.I would request you to assess his other milestones to see whether they are fitting into red flag signs or not.
His forehead appears to be prominent and this may occur in few condition one of which is vitamin D deficiency.I would like to rule out the same as in vitamin D deficiency there may be delayed motor developmental milestones but social,cognitive and verbal remains normal. I would also like to get a thyroid test done to rule out hypothyroidism which is again a very common cause of delayed development.
As you mentioned that the baby is growing more than normal,I would like to know his present weight and height.
I shall be glad to get your feedback regarding assessment of other aspects and request you to get him clinically examined by a pediatrician to find out the exact cause of delayed development.
Regards

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Brief Answer:
I would like to get him clinically examined by a pediatrician

Detailed Answer:
Thanks for follow up.Weight of 16 kgs for this age is at the upper limit of normal range.
As there is obvious delayed motor milestones,I would like to get him evaluated by a pediatrician to look for the cause and then management accordingly.
Regards

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